job 2 – cel tracer - tafe nsw · 2002-09-27 · job 2 – cel tracer page 1 of 53 welcome to the...

Job 2 – Cel Tracer

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Welcome to the Job

I'm Dan, the Cel Tracer. I hear that you've been assigned to help me with some of the tracing and scanning for the Lemon Pops TVC. Kate, our Production Manager, will have given you the brief. You should have already been to see the other production team members to get some information that will help you on the job.

We want you to use traditional cel tracing and photocopying techniques to produce four collector's art cels for the client. Four drawings have been selected from the TVC for you to trace onto cel in black ink. You will produce a second set of cels using a photocopier.

As we have moved away from the old methods of cel tracing, my main job now is to scan the animation for the Lemon pops TVC. Then Deb, the Painter, can digitally colour the frames. I'm going to give you a few scenes to scan for me. The scenes that you will scan are 3.3 and 3.4.

I'll be taking you through some activities to develop your skills before you start the job. To make sure you are familiar with all the equipment required by a cel tracer, I want you to carry out this Materials Quiz.

Resources Required

For this job you will need:

• mechanical pen and ink cartridges

• crow quill and black ink

• animation punch

• pieces of animation paper

• acetate cel

• cotton gloves

• soft cloth rag

• peg bar

• lightbox or desk

• header strips

• reusable sticky tape.


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This is what an animation punch looks like, in case you are not yet familiar with them.

Animation punch can punch registration holes in both

paper and Cel

Acetate Cel

Try to choose a cel with a thickness of .005. All cels have a light tint of some colour. The thicker cels will decrease the amount of levels of cel you can use before they dull the tone of the background. If your cel is thinner than .005 it may tend to buckle under the camera.

Make sure that the cels are clean. It is very easy to get an acetate cel dirty. The natural oils from your hands will leave a print every time you handle the cel. Cels that are greasy may refuse to take the ink properly. Before you start tracing you may want to check the cels to ensure that someone else has not touched them and left prints. Also check for dust and hair. Acetate cels easily gain an electrostatic charge so they will attract any dust and hair that comes near. You can purchase special cloths for cleaning cels that are super soft and won't scratch the cel.

To handle cels make sure that you have your cotton gloves on. Check that your cotton gloves are clean. Using the cotton gloves will avoid leaving oils and grease from your fingers on the cel. When you handle the cels touch only the outside of the cel. This way any oils that may get on the cel will be off camera. If your gloves are dirty from skin oils or from ink you can simply wash them in a washing machine to clean them and hang in the sun to dry. Fewer washes are better for longer glove life. As the gloves are relatively inexpensive it is advisable when gloves are looking worn to replace them.


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Handling acetate cel with cotton gloves

Storing Cels

Check that the cels are interleaved with sheets of tissue paper. This is the normal way to store acetate cel. The tissue paper stops dust from settling on each cel and also helps to reduce the amount of electrostatic charge that can build up on the cels. When you have traced a cel and the ink has dried, place the cel back between the tissue paper sheets, ready for the painting department.

Acetate cels should be placed in a box that is stored horizontally. Storing the cels vertically on one edge will cause them to fold or to buckle because of gravity. If the cels are left in this position for a few days they will take on this shape permanently. This is undesirable given that the cels need to be filmed on a flat plane and any creases or curves will cause the acetate to warp and bubble under the platen. Warped cels will cause unsightly glitches, highlight reflections and excessive amounts of cel shadow. Cel shadow is a natural byproduct of cel animation but an excessive amount is not desirable.


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Example of excessive cel shadow

Accuracy in Tracing

Time is money, and nobody knows this better than the Producer and the Production manager. As a result they really appreciate staff that can do their job quickly. However, the job must also be performed with accuracy. Without accuracy, poor tracing will wreck good animation causing the character to look lifeless and 'off model'.

Sometimes the difference between a good and bad tracing can be a line drawn a fraction of millimeter off centre. For example if you are tracing a pupil and you place one contour line slightly to the left of where it should be, your character is now looking in a different direction and is slightly cross eyed.


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Good and bad tracing

Activity: Tracing Errors

Some cel tracers are more accurate than others. Many types of inaccuracies can occur including:

• shaky lines

• parts omitted

• line not followed

• uneven thickness of line

• ink pooling

• inappropriate pen used

• broken lines.

It is your responsibility as a cel tracer to ensure that your traced drawing is faithful to the original drawing. Here is an activity to test your powers of


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observation and understanding.

Time Lines

In a studio production environment it is common to underestimate how long it will take to trace whole scenes. Because tracing doesn't require creative thought it is considered a process that can be done very quickly, but this is not the case. I have found that the processes of tracing, scanning and colouring together take twice as long as it does to produce the animation. This means that you should try to ensure that you receive all of the drawings to be traced with enough time to produce the tracing required for a scene.

How do you calculate how much time it takes to trace a cel? There are two ways to estimate the amount of time required. Calculate the time it took to produce the animation for a scene and then calculate 30% of this time to give you a rough estimate. The second is to time yourself tracing a typical character cel from a scene and multiply this time by the amount of frames, and cel levels.

It is hard to calculate accurately, because every cel can be very different and every character has a different level of 'line mileage' due to the drawings complexity. Some characters can get away with few lines (low line mileage) like the drawing shown below.


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Low line mileage drawing

Other drawings require a greater amount of time to express the complexities of their character (high line mileage). An example is shown below.

High line mileage drawing

I have heard of one animator who in their haste to finish a TVC produced the in-betweens directly onto cel in order to make a deadline. Needless to


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say this industry is run on deadlines and so you need to make sure that you account for tracing time. Make sure that you allow enough time to trace all of the cels from the scenes that you have been assigned.

Mechanical Pens

The use of mechanical pens like the Rapidograph will assist you in achieving a line that is consistent in thickness. The advantage of using a mechanical pen like the Rapidograph is the consistency of ink flow and a consistent line thickness. The disadvantage is a lifeless line. Unlike the other techniques that have a natural feel to them, the mechanical pen line tends to have the opposite effect and can make a drawing appear stiff, wooden and lifeless.

Using a mechanical pencil to trace can increase the amount of errors. The saving grace of the mechanical pencil is that the animation keeps moving and so the lifeless nature of the line is given life by the movement of the actual character as it animates.

Example of tracing using a mechanical pen

Check Your Equipment

Check that your tracing pen is clean and in good working order. Some ink pens that have not been used for several weeks can dry out. It is possible to save a pen that has dried up by detaching the nib mechanism and then immersing the nib in a glass of water for several hours. This is not a sure fire method but can work. You can also purchase special cleaning fluid for mechanical pens that should remove any dry ink.

If the ink cartridge in the pen has dried up or is very low, you may want to install a new one. It is very awkward to run to the shop to get a new cartridge during the middle of a job. When tracing a whole scene onto cel, you definitely want to have spare cartridges on hand.


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When installing a new cartridge it is possible to get an excess flow of ink to begin with, especially when trying to encourage the ink to flow by using centrifugal force. Having a cloth rag nearby is a good idea. To remove excess ink from a new cartridge, use the rag to wipe the nib and then trace on an old piece of paper or cel until the flow of ink is even.

When you have finished using your inking pen, you may want to store it with the nib downward, if it is a gravity fed pen. This will stop the nib from drying out. If you intend not to trace again for many weeks you may want remove the ink cartridge and clean the nib mechanism.

Mechanical pen with excess ink

Activity: Using a Mechanical Pen

In this activity, you will trace several shapes with a mechanical pen. This will give you the feel for the type of lines produced by a mechanical pen. For this activity you will need:

• mechanical pen and ink cartridges

• animation punch

• one piece of animation paper

• one piece of acetate cel

• cotton gloves

• soft rag

• peg bar

• lightbox or desk

• downloaded ZIP file.


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Steps 1. First download the ZIP file that has some examples to trace.

Download Examples

2. Print out the examples of a square, a circle and a face.

3. Punch them with the animation registration punch at the bottom of the print out as illustrated below.

Square, circle and face download with registration holes

punched at bottom.

4. Ensure that your hands are gloved.

Cotton glove on non-tracing hand to protect the cel from

skin oils


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5. Prepare your cel by ensuring that you have punched it at the bottom of the cel.

Hole punching acetate cel at bottom of cel

6. Place the drawings on the lightbox and then place the new cel on top of the drawing. Ensure that both are registered on the peg bar.

Placing cel on pegs over the original drawing


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7. Ensure that your pen has sufficient black ink. Check that your ink is flowing by drawing on a scrap of cel or paper.

Testing ink flow from mechanical pen on a scrap of cel

8. Rest your drawing hand on the cel.

Resting hand on cel and placing the pen at the top left

corner of square

9. Start with the square. First place your pen on the drawing at the far left if right handed and to the far right if left-handed. The ink can take a few minutes to dry properly and so starting towards the far left, for right handed people, should help you to avoid placing your hand on or through the ink lines that you have just drawn.

Place your pen on the intersection of two major lines on the square shape. Trace to the next intersection being careful to accurately match your inking lines to the pencil lines of the drawing beneath.


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Tracing to the next intersection

10. Rotate your tracing disk to make it easier to trace the other lines at an angle that is comfortable to draw at. Be sure not to place your fingers or hand onto the already traced lines.

Rotating the drawing disk to draw lines at a comfortable angle

11. Continue to trace line by line, from one intersection to another. Sometimes inking pens will leave a small deposit of excess ink where the pen has been lifted and placed on the cel. By starting at intersections you can hide these mishaps if they should occur.

If you find that your pen is producing a large excess of ink flow you may need to wipe your nib between tracings or get a better pen or better ink. Some inks may flow faster as they warm up from the heat produced by your hand. The only cure for this is quality ink.


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Removing excess ink flow from the mechanical pen nib

12. Fix any mistakes you make as you go. If you make a mistake on a particular line, try using a damp cloth to erase the line and then start again. If you try to fix lines after you have completed the whole tracing you will run the risk of removing other connected lines and you can make a mess of the whole cel. If you find that the whole cel has too many mistakes try starting afresh with a new cel.

Removing a tracing mistake with a damp cloth

13. Now try the circle. Obviously it is very hard to draw an accurate circle in one continues line with one continuous motion. You have to start and stop again numerous times. So you must learn the technique of starting and stopping the same line. This will occur many times in your tracing career.

Start on the far side of the circle and start tracing the circle with some momentum so as to avoid the excess ink from pooling and causing a spot at the start of a line. Continue to trace until just before you feel discomfort from the contortion of your tracing hand. Trying to draw


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beyond what your hand can comfortably manage will cause you to draw lines that are not accurate.

Tracing on far side of the circle

14. Turn the tracing disk to an angle that allows you to draw comfortably. With great precision start tracing over the end of your first line with a little momentum. By tracing over your old line you can match the new line exactly. This is by far the most difficult technique in tracing and takes much practice to perfect.

Continue this technique until you have your complete circle. Ensure that you meet the beginning of the traced line and raise your pen nib while still moving so as to minimize any excess pooling of ink.

Raising the pen nib after the lines have joined to avoid

ink from pooling

15. Test your tracing by raising and lowering the cel sheet. Sometimes when the thickness of the ink line outweighs the pencil line, you can think that you have traced the line accurately when in fact the line is being masked by the ink line and you have not captured the true curve or angle of the original drawing. Raising and lowering your cel will help you to see any gross misrepresentations.


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Raising the cel during the process to check the accuracy of

the traced lines

16. Let's try the face. Use a combination of the two techniques above to trace out the face. When you have finished, check the accuracy of your tracing by raising and lowering the cel. As you trace, try to be extremely accurate to the original drawing lines and at the same time try to capture the essence of the picture so as to avoid making it lifeless and stiff. You can do this by concentrating on the shape of the line rather than the line itself.

Raising the cel to check the accuracy of the traced lines

Crow Quill

The crow quill is a pen with a pointed nib tip that uses ink from a well. Crow quills can be used by a skilled tracer to achieve an artistic effect such as thick and thin lines on the same drawing. Tracing a drawing with


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tapering lines is very desirable for collection art because the effect looks quite good and the viewer only sees the one cel at a time.

The different line types that can be achieved by use of a

crow quill

Before you start on the production drawings, I'd like you to carry out an activity using a crow quill.

Activity: Using a Crow Quill

Try tracing three shapes, a square, circle and face with a quill pen. This will give you the feel for the type of lines produced and the difficulty level of using such a pen.

1. First download the ZIP file that has some examples to trace.

Download Examples

2. Print out the examples of a square, a circle and a face.

3. Punch the drawings and place them on the lightbox.

4. You will also need to punch a clean sheet of acetate cel and place it over the drawings. Remember to put on your gloves before handling the cel.

Placing cel on pegs over the original drawing


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5. Place the crow quill into the handle.

Inserting a crow quill nib into a handle

6. Remove the lid from your inkbottle.

Removing the lid from the bottle of ink


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7. Dip you nib into the inkbottle and remove excess ink onto scrap paper.

Dipping the crow quill nib into the inkbottle

8. Place your quill on the cel at the top corner of the square and trace, with accuracy, down to the bottom of the square. Lift the tip as soon as you reach the corner. Be careful to start with light pressure then increase your pressure as you stroke then lighten you pressure again as you finish the stroke. The quill is pressure sensitive and will supply more ink with more pressure applied.

Placing the nib at the top left corner of the square


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9. Continue to trace out each line in the same way. Ensure that the lines are accurate. Remove any non-accurate lines with a damp cloth, then retrace.

Removing a tracing mistake with a damp cloth

10. Ensure that you refill the nib before your ink supply to the nib runs out. When you have finished the square try the circle and then the face. Be sure to rotate the drawing disk when necessary to draw at a comfortable angle. Lift the pen nib when finishing a stroke to avoid excess ink pooling.

Rotating the drawing disk to draw lines at a comfortable angle


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Tracing the Collectors' Cels

The collectors' cels will be based on Lemon Pops TVC cleaned-up drawings that reflect some of the main storyboard panels. For tracing the collectors' cels you should already have printed copies of:

• three model sheets

• five storyboard pages

• two X sheets

• eight cleaned-up drawings.

The Scenes that the collectors' cels will illustrate are:

• Scene 1.1 Cont'd

• Scene 1.3

• Scene 2.1 Cont'd

• Scene 3.2

As George, the Clean-up Artist, has explained, each character is a separate cleaned-up drawing. You will be tracing each character onto a separate cel. Once they have been painted, the characters from each scene will be composited with the background to produce the final cel art. I want you to start with the drawing of Lemon Pops from Scene 1.1 Cont'd. This panel (shown below) shows Lemon Pops greeting the other characters. Notice that there are three characters in this scene:

• Lemon Pops

• Fruit Thingies

• Coco Shmacks

Storyboard panel from Scene 1.1 Cont'd


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Tracing Requirements

For this job we have to produce a high quality trace so we have been given ample time to produce the finished cels. Trina, the Art Director, requires the line type for the clean up artwork to be a thin solid black line. It is up to you whether you use a mechanical pen or a crow quill. You should have carried out an activity with each of these pen types, so you can choose whichever one you prefer for job.

Personally, I prefer to use a .05 Rapidograph pen with Rotring's Kapillarpatrone cartridge and MF ink, which is specifically designed to draw on tracing paper and drafting film. Using the Rapidograph pen on cel will give an even thickness of line.

In animation, variation in line width is an undesirable effect, as it will give unwanted line movement during the animation. If you do want this effect then you can deliberately exaggerate the effect by tracing loosely with a quill or felt tipped pen. You will need 12-Field cels punched with registration peg holes at the bottom of the cel. There are eight drawings to be traced so you need at least eight cels. I suggest you have 10 to 12 ready, in case you make mistakes.

Equipment for Tracing

Gather together the materials and equipment you will need for cel tracing:

• animation punch

• peg bar

• lightbox

• thin Rapidograph pen - 0.5 (or crow quill)

• black ink cartridge for the pen (or black ink for crow quill)

• cloth rag

• 12-Field acetate cel

• cotton gloves.


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Materials ready for tracing the production cels

Checking the Drawings

You first need to check the drawings to make sure there are no problems. Check that the characters have all of the body parts that they should have according to the model sheets. (You should have three model sheets and received useful information about them from Trina, the Art Director.)

Check that you understand each of the parts of the character. It helps to understand the character or object you are tracing, rather than just tracing the lines that you see in front of you.

Below are the final clean up drawings for Scene 1.1, composited with the background layout. Remember that you will be tracing each of the three characters onto a separate cel and combining them according to the cel levels shown on the X-sheet. I will show you how to trace Lemon Pops from Scene 1.1 step by step. Then you will be on your own.

Composite of final clean up drawings with background layout

from Scene 1.1 Cont'd


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Activity: Tracing Lemon Pops from Scene 1.1

As I provide step-by-step guidance, trace the first of the cleaned-up drawings from Scene 1.1 Cont'd using a thin ink pen. This first drawing is a typical drawing of Lemon Pops without sugar.

Lemon Pops without sugar from Scene 1.1 Cont'd

1. Put on your cotton gloves before handling any acetate cel.

2. Place the drawing of Lemon Pops from Scene 1.1 onto the pegs.

Cleaned-up drawing of Lemon Pops from Scene 1.1 on the

pegs


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3. Place a clean sheet of punched acetate cel onto the pegs over the drawing.

Placing a punched sheet of cel onto the pegs over the drawing

4. Test your inking pen on a scrap of paper or cel to ensure that the ink is flowing freely. Wipe any excess ink from the nib with a cloth rag.

Wiping excess ink from the nib onto a clean cloth rag

5. Always start tracing the character on the opposite side to the hand with which you will trace:

• If you are right handed, start with the lines on the left side of the character.

• If you are left handed, start with the lines on the right side of the character.

This way you will not put your gloved fingers and hand through the freshly drawn lines as you move across the page. It is very easy to smudge freshly drawn ink.


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Start with a corner point of the character. Trace out a complete line until you reach another intersection of two lines. Trace with great accuracy. Try not to lose the shape of the line that the clean-up artist has prescribed.

Starting to trace at an intersecting point furthest from the

tracing hand

6. Lift the cel from the drawing to see if your line has accurately traced the original drawing. If you have made a mistake, use a damp cloth rag and your fingertip to remove the line and redraw when the cel has dried.

Continue tracing the lines from intersection to intersection. Check accuracy occasionally by lifting the cel.

Lifting the cel to check for accuracy in the traced line

7. When drawing circular lines, like the eyes or straight lines that occur on angles, it may help to turn the lightbox disk to an angle at which it is comfortable to draw.


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Turning the drawing disk to trace circular lines at a

comfortable angle

8. If you cannot complete a line in one move then you will have to take great care to accurately stop and start the line at the same position. This can be difficult especially if your pen produces excess ink on contact with the cel.

To overcome any excess pooling, try to start and finish your line with the pen moving. This way the ink doesn't have time to pool. Also, start tracing your line over the top of the end of the first line you have just drawn rather than trying to put your pen exactly where the first line stopped. This should hide any stop and start marks in the line. This is illustrated by the series of four drawings below.


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9. When you have completed tracing all of the character, lift the cel up and down to check that you have traced all of the characters contour lines. If you were to omit any parts on one cel when tracing a scene for filming it would be obvious when they are played in sequence and the whole scene would have to be shot again.

Lifting the cel to check for accuracy in the traced line

10. If you see any body parts or lines that you are unsure about consult the original clean-up construction drawings. Sometimes they have labels for body parts that may be hard to identify. Below is the clean-up construction drawing for Lemon Pops.


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11. Label the finished cel between the peg holes, with the scene number. Place the finished traced cel with the tissue paper to the drawing side being careful not to fold or crush the cel.

Now you should be ready to trace the other two character cels for this Scene, following the same steps you used for Lemon Pops.


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Activity: Tracing Coco Pops from Scene 1.3

Here is the storyboard panel for Scene 1.3. Following the same steps you used to trace Lemon Pops, trace Coco Shmacks onto a 12_Field acetate cel.

Coco Shmacks from Scene 1.3

Activity: Tracing Characters from Scene 2.1

Here is the storyboard panel for Scene 2.1. Following the same steps you used to trace Lemon Pops, trace Jenkins, Mr Crisp and Lemon Pops onto three separate sheets of 12_Field acetate cel.

Mr Crisp and Jenkins, with Lemon Pops in

the background from Scene 2.1


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Activity: Tracing Lemon Pops from Scene 3.2

Here is the storyboard panel for Scene 3.2. Following the same steps you used to trace Lemon Pops in Scene 1.1 Cont'd, trace Lemon Pops onto a 12_Field acetate cel.

Lemon Pops with sugar from Scene 3.2

Requirements for Photocopying onto Cel

Dave, the Director, wants you to photocopy the same drawings that you have traced from the Lemon Pops TVC to compare the image quality of tracing with that produced by photocopying. If the pencil qualities really show up well in the photocopied process, we will use the photocopied cels for the final Cel Art.

You should already have the eight selected drawings taken from various scenes of the Lemon Pops TVC. In comparison to tracing, for photocopying it is essential to have final, clean drawings as every mark will come out in the photocopy.

Ensure that the selected drawings are cleaned-up drawings rather than ruffs and that the line work is dark enough and consistent in thickness (not light sketchy lines). Check that all of the lines join and there are no glaring mistakes on the drawing. Make sure there are no messy constructions lines, or drawing notes. If you should find any of these


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unwanted markings report them to your supervisor. Compare the two images below to see what I mean.

Using a Suitable Photocopier

A standard photocopier cannot be used for copying to acetate cel. In a standard photocopier the fuser's heated roller, which melts the plastic material in the toner and fuses the pigment to the paper, is too hot for the acetate cel. It will cause the cel to buckle and warp which is most undesirable for an animation cel. For this reason the copier needs to be modified. In a studio that uses the xerography process the photocopier can be fixed with a set of peg bars on the copier. This ensures for the most part that


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when the drawings are scanned they will be relatively close to the correct position on the cel. You may need to experiment with a few sheets to get the pegs positioned correctly.

Place your drawing onto the pegs, then close the lid. You will need to feed the acetate sheets in through the manual feeder tray, as the sheets are too heavy to be fed by the automatic tray feeders. When your drawing is in the correct position on the peg bar and your sheet of cel is loaded in the manual feeder tray, hit the copy button. You should receive the copied cel within a few seconds.

Take the cel out and examine it for line quality. If the outline is too light or too dark you may have to adjust the darkness and lightness controls. Remember when you are copying a whole scene that you must use the same settings for every cel so that the outline doesn't change in thickness and darkness throughout the scene. Be careful not to get any grey areas on the cel. Photocopiers tend to photocopy white pages as light grey if the settings are not correct. The desired output is a strong dark line and clear cel in all other areas.

Activity: Photocopying and Registering the Cels

You will need the eight cleaned-up drawings and approximately 10 - 12 sheets of 12-Field acetate cel. This number includes some extra cels for initial testing of the photocopier settings. Make sure to use a photocopy machine capable of copying onto acetate cel, then follow the steps below.


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1. Copy one drawing onto a cel. Ensure that the line work is of suitable standard. If not, discard this cel and adjust the contrast on the copier.

2. When the line work is of suitable standard copy the other cels, making sure you keep the same settings for every cel.

A photocopied cel doesn't have the registration holes in it. Once you have completed the photocopying, you need to register the cels. This is particularly important for the Cel Art that will be made up of a composite of a number of cels. A simple method for producing the registration holes makes use of a header strip. A header strip is a self-adhesive strip that adheres to the cel to provide the registration.

Header strip

3. Place the original animation drawing onto a desktop that has a fixed peg bar.

Original drawing


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4. Line up the acetate cel accurately with the original drawing. Place some pieces of reusable sticky tape at the top of the cel, taping the cel to the desktop so that it cannot move out of position.

Taping the photocopied cel on top of the original

5. To use a header strip, your cels need to be trimmed so that the cel stops before the pegs. First lift the cel into the air, leaving the original drawing on the desk. Tape at the top of the cel should hold it in position.

Lifting the cel up


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6. Place the header strip over the pegs and peel back the wax covering, which exposes the sticky surface on the header strip. Then gently roll the cel back down into position so that the cel adheres to the sticky header strip and remains flat.

Header strip in place

7. When you have stuck the strip to the cel you can transfer the drawing numbers to the header strip by writing between the pegs. Most strips can be written on.

8. Place the cels into four separate groups for Cel Art 1, 2, 3 and 4, placing the cels for the composite Cel Art in the correct order according to the X-sheet. Place the original drawings against the inked side of the cel.

Scanning Requirements

Check that you have all of the drawings before you start scanning. You can check them against the X-sheet to ensure that you have them all. You should scan the field guides when you scan the drawings. The field guide


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will not be used in the actual animation but it helps you to scale the animation to the correct size when you composite the final images.

The job is to scan two scenes for the Lemon Pops TVC. The first scene that you will be scanning is Scene 3.3. It has two characters that have been placed on separate cel levels. On the top cel level is Wheat Bricks. His column is noted at the top by the initials WH. On the cel level next to Wheat Bricks is Fruit Thingies. His column has the initials FR.

If you look down the X-sheet you will notice that Wheat Bricks has only four drawings to be scanned in this scene. Some of them are used twice. Wheat Bricks has less movement because Fruit Thingies is doing a lot of movement. We don't want Wheat Bricks to distract the audience from the main action. Fruit Thingies has 28 drawings in total. Most of these as you can see from the X-sheet are exposed at two frames each however there are a few drawings that are only exposed on one frame.

In scene 3.3 you will have a total of 32 drawings, and one field guide to scan into the computer.

Here's the storyboard panel for this Scene.

Storyboard panel

In Scene 3.4 Coco Shmacks gives Lemon Pops a hug and expresses his new appreciation for Lemon Pops. Because the two characters are interacting with each other it was decided by the animator that it was necessary to draw them on the same cel level. If you have a look at the X-sheet you will see that only one column has been used. There are a total of 15 drawings, and one field guide, to be scanned for this scene. The majority of drawings are exposed for two frames each, except for one drawing that is exposed for only one frame.


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Here is the storyboard panel for Scene 3.4.

Storyboard panel for Scene 3.4

Technical Criteria and Image Quality

For our TVC we require the following specifications: PAL, 4:3 ratio, at 768 by 576 pixels which will be transferred to Digital Betacam Tape. That means that we only require our final bitmaps to be 768 by 576 pixels. Because the animation is done on a 9 field we will need to scale the image up slightly to meet the PAL pixel resolution. Normally the scale option on your scanning software is set by default to 100%. If you scan the animation at screen resolution (72Dpi) but increase the Scale percentage to 125% it should easily fill the PAL screen size with some room for bleed.

I hope you've learnt about scanning resolution and Bitmaps versus Vectors in the Studio Tour. If not take a look at it now. It is important to know what types of files the animation system you will be using can work with before you start scanning. These days vectors are considered preferable to bitmaps.

If your animation software uses bitmap images rather than vectors, each image needs to be scanned at the same size to ensure correct registration to each other. This means that if you scan some images from the scene at a scale of 125% and a resolution of 72 Dpi, you should scan all of your images with the same settings. Scanning the drawings at 72 Dpi should save you a lot of hard drive space.


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If you do need to perform any camera moves such as truck ins, you should scan the scene at a higher resolution such as 150 to 300 Dpi depending on the amount of zooming you will need to do. The two scenes from the Lemon Pops TVC, 3.3 and 3.4, don't have any complex camera moves and so you should be able to scan them at 72 Dpi and a Scale of 125%. The problem with bitmaps at high resolutions is that they require a lot of disk space to store the images and can slow down your compositing software if you have a lot images.

The image below shows a picture of a scene where the camera will zoom into the castle. So that the castle doesn't become blurry or pixilated when the camera zooms in we need to scan the whole image at a high resolution so that we have more pixel information to play with.

72 DPI image with PAL view of camera move

Activity: Scanning a Scene from Lemon Pops TVC

I will guide you through this activity using Adobe Photoshop. The desired final output is a thin black line. To prepare scans for a vector-based animation system, scan each of the final drawings following the steps below.

(Please use these steps as a guideline only for your particular setup. If necessary, consult any documentation that comes with the scanner, and the scanning software. The exact instructions for scanning images will depend a great deal on the scanner you are using, the software it employs, and the interface of the image editing software.)


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1. Fix the registration bar to the side of the scanner with tape.

Fixing a peg bar to the side of a scanner

2. Place the drawings one at a time onto the registration pegs.

Placing the animation drawing onto the peg bar.

3. Close the lid of the scanner.

Lowering the scanner lid over the drawing


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4. Open your scanning software. You should be able to choose File > Import > name of your scanner.

Opening the scanning program

5. Set the parameters for your particular scan. Select full platen (that is the largest scanning area available).

Selecting Full Platen, which is the largest possible

scanning area


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6. Choose Grey scale or B/W photo as the animation at this stage contains no colour values.

Select Greyscale or Black and White

7. Choose an Output Resolution of 600 Dpi. (Please note that if you are using a bitmap based animation system you need only scan at 72 Dpi with some scale increase (e.g. 125%) for the scene without camera moves and about 150 to 300 Dpi for scenes that do have camera moves).

Selecting 600 dpi to achieve a high-resolution image


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8. Preview the image to test for image quality. A preview is a low level (and thus quick) scan that lets you preview how the image will appear.

Previewing the image to be scanned.

9. If necessary, rotate the view so that the image is right way up.

Rotating the preview so that the final image is the right way up

10. If the previewed image looks grey rather than black and white adjust the levels in the scanning software by darkening the mid tones and reducing the white level so as to turn the dark grey areas into black and the light grey areas into white.

The settings I used for Input levels are 0, 160 and 240.


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Changing the inputs levels for scanning to

get the cleanest black and white line

11. Adjusting the contrast will help to give a definite black and white outline for the vector converter to follow.

Adjusting the contrast to darken the outlines and turn any light grey pixels to white

12. If you make any changes to these settings please record them on the scene folder.

13. Run your preview again.


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14. Press the scan button.

Click the scan button to scan the animation

15. When the image has been scanned save it according to the file naming procedure.

16. Then replace the drawing on the scanner with the next drawing in the sequence. The scanning software's settings should remain the same for the rest of the scanning procedure.

17. Scan the remaining drawings in the scene.

Final scanned bitmap image

Registration

If your animation software does not support peg hole registration (that's automatically registering each drawing to the other using the peg holes in the drawings) then you may need to ensure that you have a black bar at the top of each scan. You can do this by placing a black strip on your scanner against the glass. When the scan is converted to vectors this black shape can be used to register each drawing to the others using the align tool.


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Black strip at top of scanner provides registration for images

converted to vectors

If your software does support peg hole registration you may need to place a black strip on the scanner lid to ensure that the peg holes are scanned in black (please consult your animation software for exact method).

Black strip on the scanner lid provides a peg hole silhouette

for some programs to register drawings

Congratulations on finishing the job! Now it's up to Deb, the Painter, to digitally colour the Scenes you scanned.

Don't go yet. I thought you might be interested in hearing more about the techniques of traditional cel tracing. You never know when they might come in handy.


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Traditional Cel Tracing

Traditionally, every cleaned-up and in-between drawing would have been traced onto acetate cel. As the cel tracer, you would have to check that you had sufficient acetate cels to complete your job. If you were tracing a whole scene you would need as many sheets of acetate as there are drawing numbers on the X-sheet.

For every drawing noted on the X-sheet there should be some character or part of a character to trace on cel. That means you would need one cel for every drawing the animators and in-betweeners produce. As you can imagine this would likely be hundreds of cels per scene.

Before you started tracing you would normally flip the scene to check for any problems and ensure that all of the drawings are present according to the X-sheet. If any are missing this will cause major problems further down the track. Even with good clean-up artists and in-betweeners, it is still possible for problems to creep right through the process with no-one picking them up. If the cel tracer manages to stop them from going further into the film, then they will have saved a lot of wasted time and effort in 're-dos'.

Some of the techniques a traditional cel tracer would need to understand are:

• held cels

• matchlines

• tracebacks.


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I'll now explain in detail what I mean, in case you are ever required to use these traditional methods.

Held Cels

When tracing a held cel you will need to ensure that the line work is perfect. Unlike most cels that are held for 1/25th or 2/25ths of a second, this drawing will be held for more than two frames - most likely many frames - so the audience will get to see it very clearly. The important thing about held cels is that sometimes other parts of a character will need to match to the held cel perfectly. In these cases you will need to keep the held cel close at hand so that you can place it under the cel being traced and trace up to the outlines of the held cel with great accuracy.

When you have finished with a held cel return it to the stack of finished cels in the order that it will occur when shooting so that the cameraperson doesn't have to go looking for it through hundreds of cels.

The body is to be held and so it is traced on to a cel on its

own.


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The left arm and head are both moving and so they are traced on to a cel.

Left arm and head are animated

To trace the arm meeting the body, the held cel is traced to produce an accurate line.

Matchlines When a character or object needs to look as though it is moving behind an object in the background, the animator draws to a matchline. There will be an indication of the matchline on a layout sheet called the 'matchline layout guide'.

When tracing to a matchline, place the matchline layout guide onto the lightbox, turn on the backlight and trace up to the matchline. Trace along the matchline at the regions where the character intersects the matchline.

If the production calls for a matchline to be a self-line, that is where the outline colour is the same as the fill colour then you will need to trace the matchline with coloured inks or paints according to the colour model.


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The following three images show an example of the use of a matchline in animation. The first image shows the character composited over the background. Note how the character has to be drawn up to the doorway but no further, so that his body appears to be behind the wall and his head is coming through the doorway. His fingers appear over the edge of the doorway.

A character on a background peering around a doorway

This is achieved by the use of a matchline. The matchline corresponds to the edge of the doorway as shown below.

Matchline layout guide lines up with the front edge of the

doorway


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The character is traced up to the matchline but no further, except for his fingers, which need to appear over the wall.

The body is traced up to the matchline so that the character appears to be coming through the door.

Tracebacks In animation a trace back is used when a part of a character stops moving. Rather than making it into a held cel it is traced again and again from the same key frame so that there is only a slight movement. The line looks alive but does not overtly wobble so as to be distracting. When tracing back on cel you need to follow the same rule as the in-betweeners, always traceback from the same drawing, usually the first key frame. Let's look at an example.

In the Lemon Pops TVC, Lemon Pop's feet are not moving from Drawings 25 to 35. You would start tracing Drawing 25, then when you trace Drawing 26 you will need to put the traced cel 25 back onto the pegs to trace out the feet. The rest of the character can be traced from Drawing 26. For Drawing 27 and up to drawing 35 you should use the traced cel 25 to traceback the feet. This way the line stays exactly the same on each frame. See the image below.


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Cel 27 is placed on top of Cel 25 to traceback the feet so

that they look the same.

job 2 – cel tracer - tafe nsw · 2002-09-27 · job 2 – cel tracer page 1 of 53 welcome to the...

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