how to print pepakura designs - amazon web services · 2019-09-18 · step 5 — check scale models...

MatterHackers

How To Print Pepakura DesignsPepakura is a technique commonly used in the cosplay, and replica prop communities for

constructing things out of paper. In this guide we will walk you through taking your pepakuradesigns and making them 3D printable.

Written By: Tyler Anderson

How To Print Pepakura Designs Draft: 2018-03-20Guide ID: 38 -

This document was generated on 2019-09-18 05:18:36 AM (MST).

© 2019 matterhackers.dozuki.com/ of 22

INTRODUCTION

Pepakura models are designed to be cut and folded out of paper. This causes a few challengeswhen you try to 3D print them. First, they have no thickness, so we will have to create the interiorwalls in order to give them some volume. Secondly, they are usually composed of few polygons, sowe will need to smooth the surface.

This guide was written specifically for my build of a MK III Iron Man suit, but I think it could be usefulfor any sort of costume.




Step 1 — Export OBJ from Pepakura Designer

First we will need to export the model from Pepakura Designer.

To do this, go to File > Export > Texture Editing > 3D Model with UV Info .




Step 2 — Import into Blender

We are now going to take the model into Blender and make some modifications to get it ready for3D printing.

Many of you may already be familiar with basic editing in Blender, but I'm going to try and be asthorough as possible for those that aren't. The best way to learn things is to have a specific taskyou want to accomplish, or problem you want to solve. I hope this guide will be a good way fornewbies to get to know this extremely powerful program.

First you will want to delete all the objects in Blender's default scene. To do this, press A untileverything is selected, then press X to delete them.

To import the OBJ file, go to File > Import > Wavefront (.obj). Select the file you exported in step 1.




Step 3 — Navigating in Blender

Here are the basics of getting around in Blender.

Drag MMB (Middle Mouse Button): Rotate view

Shift + MMB: Pan view

Scroll wheel: Zoom in/out

RMB (RIght Mouse Button): Select an object




Step 4 — Center the objects

When your model is imported, it will likely be off in the distance. Lets move it back to the center ofthe scene.

Select the group by right clicking on it.

Move it to the center by dragging the arrows on each axis.

You can also move things by pressing G.

To make things easier, you may want to reset the object's origins. To do this, go to Set Origin >Origin to Geometry.

At this point you will probably also want to save the model with CTRL-S.




Step 5 — Check scale

Models in Pepakura may have a scaling factor that is not applied to them when exporting. Letscheck the scale in Pepakura and adjust our Blender model accordingly.

In Pepakura Designer, go to 2D Menu > Change Scale > Set Scale.

Copy the scale value.

In Blender, right click on your model to select it and then press N to bring up the ObjectTransformation panel.

Change the scale of all three axes to what you copied from Pepakura.




Step 6

You will also probably want to adjust the scaling factor so that the costume fits you better. To helpyou choose the correct size, you can take measurements from the model in Blender.

Select the object and then switch to Edit Mode.

Press A until everything is deselected.

Go to Grease Pencil > Ruler/Protractor

Hold CTRL and drag the mouse from one point to another.

Press ESC to clear the measurements.




Step 7

You can also take the same measurements in Pepakura.

Right click anywhere in the 2D view and select Measure Distance between Two Points.

Now you can click on any two points in the 3D view to get a measurement.




Step 8 — Separate objects

Many Pepakura designs have multiple pieces on the same sheet. When you import them intoBlender, they all come together as one group. We need to separate them in order to work on themindividually.

Select the group and switch to Edit Mode, if you are not there already.

Press A until nothing is selected, then right click on one piece to select one of its vertexes.

Press CTRL-L to select the entire piece (all linked vertices).

Press P then choose Selection to separate that piece from the group.




Step 9 — Remove support structures

Now lets start working on cleaning up these pieces. Many Pepakura models have built in supportstructures, which are useful when building molds but not so much when 3D printing. We are goingto remove these.

Select a piece and go into Edit Mode.

Switch to Face Select mode.

You can select faces of the support structures by right clicking on them individually, but I find iteasier to use Circle Select.

Press C then click to select faces touching the circle.

You can use the scroll wheel to increase/decrease the size of the circle.

When you are done selecting, press ESC.

To delete the faces, press X and then select Faces.




Step 10

Tip: You can hide the pieces youaren't working on right now byclicking the eyeball icon next to themin the Outliner.

Also remember to save yourprogress as you go (CTRL-S).




Step 11 — Enthicken

The main problem with Pepakura models is that, since they are made to be printed on paper, theyare only a surface. They have no thickness or volume. This means that there is not actuallyanything to print (i.e. the printer has nothing to fill in).

There are a couple ways we can give the model some thickness. I'll go over doing it automatically,and a couple of manual methods for different situations.

The easiest way to do this is with the Solidify modifier.

Select your object, then go to the Modifiers tab of the Properties editor.

Click Add Modifier and then choose Solidify from the Generate section.

Increase the thickness to whatever you think is best. I think 3.0 is a good starting point.

If you want to make the changes permanent, you can hit Apply. This is not really necessary,though. You can leave it as is, which will allow you to edit the modifier later.




Step 12

Here is an example where we don'teven need to use the Solidifymodifier. This piece has a front andsides. All we need to do is give it aback.

Switch to edge select mode andselect one of the outer edges.

Go to Select > Edge Loops to selectthe rest of the ring.

Press ALT+F to fill in the back withpolygons.




Step 13

This piece is tubular. We need togive it an inside.

Go into edit mode and press A toselect everything.

Press E to extrude. This will make acopy of the mesh that is linked to theoriginal around the edges. You canmove this copy around with themouse, but in this case we want tokeep it in the same place so justpress ESC.

Now press S to scale down thecopy. We are going to turn it into theinside surface.

We want the inside of this tube to bejust as tall as the outside, so pressSHIFT+Z to tell blender not to scalethe Z axis. Conversely, you couldpress Z if you wanted to scale onlythe Z axis but not any others. Thesame goes for the X and Y axes aswell.

Move the mouse until the tube is theright thickness, then press ESCwhen you are done.




Step 14 — Check for thin sections

Once you have given the mesh some depth, it is important to check and make sure there is nointersecting geometry, or thin sections that may be flimsy or not print at all.

You can use ALT+B to slice open the mesh and see inside of it.

Here you can see a part of the inside that's sticking through the outside. I'll need to fix this bydeleting faces and moving things around.

This part is also very thin and might not print well.

You can also switch the view to wireframe mode, to make everything transparent.




Step 15 — Splitting pieces

You may want to split parts into multiple pieces. For instance, if you want to print sections indifferent colors or if the whole piece is too large for your printer. In this case I am going to split IronMan's thigh into the gold section and the red section.

We need to select the line where the cut will be made. Select one edge and then keep selectingmore using SHIFT or CTRL.

CTRL makes it easy by selecting the shortest path between the first line and the one you click on.

Press V and ESC to rip the mesh along the line you selected.

Press CTRL+L to select the entire linked section, then move it away from the rest.

Press P to ungroup it from the original.




Step 16

We now need to fill in the space where the cut was made.

Select one of the edges of the open area, then go to ``Select > Edge Loops".

Press ALT+F to fill in the area.

Step 17

Sometime the auto-fill will not work well, in which case you will need to add faces manually.

Select 3 points, then press F to make a face from them.




Step 18 — Clean up mesh

Before we continue, lets make sure there are no problems with the mesh.

Normals are what determines which side of a face is the inside, and which side is the outside. Ifthese are reversed, it can cause slicing errors.

Select all then go to Mesh > Normals > Recalculate Outside . If you see any faces change colorslightly, it means they were reversed before.

Now lets check for non manifold geometry. These are parts of the mesh that either have holes orare intersecting with itself.

Go to Select > Select All by Trait > Non Manifold .

Any parts of the mesh that are now selected have issues. You will need to manually fix these. Thebest way is to probably delete those faces and reconstruct that area.

One thing that often leads to non manifold geometry is vertices which are very close to each otherbut not actually linked. To fix these, select all and then go to Mesh > Vertices > Remove Doubles




Step 19 — Smooth surfaces

Congratualtions, we now have a printable mesh. However, it doesn't look that good. Unless youare cosplaying as a low polygon video game character, you are going to want to smooth things out.

To smooth things out we are going to use Blender's Subdivision Surface Modifier. Open to theModifiers tab and then go to Add Modifier > Subdivision Surface.

The setting you want to play with now is the number of subdivisions ( View, not Render). I generallylike to do 3 or 4. The more subdivisions, the smoother the surface. However it will also make morepolygons which means larger file sizes and slower performance.




Step 20

Blender's smoothing algorithm will, by default, round off all edges. Even edges you may want tokeep sharp. To prevent this, we need to tell it which edges we want to preserve by creasing them.

Lets start off by temporarily disabling the Subdivision Surface modifier. You can do this by clickingthe eyeball icon.

Now lets select the edges we want to crease. An easy way to do this is by going to Select > SharpEdges. This will select all edges with a sharp angle.

Play with the sharpness threshold until it looks like it has most of the important edges. It does nothave to be perfect. We can add or remove more later. This is just to give you a good starting point.

Crease the edges by pressing SHIFT+E then type 1.0 and press ENTER.

To uncrease an edge, you would type -1.0 instead

You can now unhide the modifier to see how it looks, then go back and crease/uncrease moreedges as needed.




Step 21 — Print!

Thats it! You now have a model thats ready for printing. Go to File > Export > Stl (.stl) to export thecurrently selected object.

Now bring it into your favorite slicer and start printing.




how to print pepakura designs - amazon web services · 2019-09-18 · step 5 — check scale models...

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