CGS 3220Lecture 3

Introduction to Computer Aided Modeling

Instructor: Brent Rossen

Adding Details – Overview

How to extrude polygonal faces How to move faces How to delete faces How to combine objects How to move the pivot point About construction history How to delete construction history

Opening your file

Ctrl+o or File > Open Scene If you can’t find your scene, you haven’t set

your project Either, cancel and File > Project > set or click

Set Project… in the bottom right of the dialog box

Since we’ll be making changes, be sure to save the scene as a new scene, File > Save Scene As…, name it “Garage02”

Garage Opening

To make the garage door, let’s start by changing the room’s geometry and make an opening

First, let’s add some geometry by changing the number of subdivisions

Select the garage input in the channel box Click drag all the subdivision items and

MMB+drag to the right to increase the attributes to 5 (virtual slider)

Extruding Polygonal Faces

Extruding polygons is one of your main methods for making changes to geometry.

To extrude faces: Hit F11 to display faces in component mode Select the appropriate faces for the garage Edit Polygons > Extrude Face An all in one manipulator will appear Use the translation portion of the manipulator,

grab the blue axis and bring it in a little to make a border

Extrude and Scale

Edit Polygons > Extrude Face again

LMB+drag the square to scale the extruded faces smaller in z, y

LMB+drag the yellow translation arrow to move the bottom border even with the floor

Door Frame

Extrude again Translate the faces

towards the outside of the garage to create the inside door frame

Now delete the selected faces This creates the door

opening

Garage Door

Now lets make the door to fit in the opening We’ll model a single plank Then duplicate it like last lecture to make the rest Then combine the pieces together to make a

single door Create > Polygon Primitives > Cube Move the cube to the bottom of the door

frame Scale the cube into a plank, rename it plank

One More Plank

Rotate the plank a little towards the inside of the garage

Edit > Duplicate Options, reset, then dup

Move the second plank up so the bottom touches the top of the last one

Scale both planks out until they are just touching

Many More Planks!

Figure out the difference in height by subtracting the height of the bottom plank from the height of the top using the channel box

Edit > Duplicate options Copies: 6 Translate Y: top – bottom

Combining Polys

Now that we’re done with making the door, let’s simplify door manipulation by combining them all into one big piece

With them all selected: polygon > combine Rename the new model to garageDoor

Adjusting Pivots

When new objects are combined, the pivot point is placed the center of the world, we want it in the center of the object To automatically center the pivot

Modify > Center Pivot To move the pivot point manually, press the insert

key (Home on Macs) Move it around, then hit insert again to get back to

regular manipulators Let’s move it so the garage door appears to open

correctly

Doorknob

Now we’ll give the door a doorknob, so our characters have something to grab when they want to open it

Make a new polygon primitive cube and rename it knob

Input: Width: .5, Height: .25, Depth: .25 Subdivisions Width: 2 Move it to an appropriate place on the door

Symetric Faces

Extrude the two faces on each side of the front cube as shown

After you extrude, you can move one face, and the other face will be moved symmetrically. The faces are moved

based on the face’s own normal

More Knob

Continue extruding and moving until you get the look in the image

To finish it, smooth the doorknob

RMB > Object Mode Polygon > Smooth

Construction History

All the different tools used on the doorknob are still accessible from the inputs section of the channel box

Select one of them and you can make changes to what you have already done, without losing work you’ve done later The extrude manipulator is displayed if you select

one of them Let’s try changing some settings

Deleting History

Keeping all that history around is intensive for both calculation and size especially later when you are working with high

poly characters Now that we’re sure the doorknob is done,

let’s get rid of the history Edit > Delete by type > History To delete all history in the scene: Edit > Delete all

by type > History

Conclusion

Save your scene! There’s lots more to polygonal modeling, but

you can create a wide range of things with what you’ve just learned

We’ll get more in-depth with modeling later, for now, we’ll try to experience many different 3d Modeling and Animation topics

In the next lesson, we add colors to the scene with shaders and textures