I can't afford a 3D printer. You probably can't, unless you own a business that might make marginal profit from the investment. So here's the next best thing, and all you need is a regular printer and some paper (obviously). It is a slightly larger pain in the ass depending on the complexity of the model, and therefore far more satisfying. It can even be quicker than 3D printing, depending on what you make.
I conceived this method by reverse engineering the texturing process in 3D tools. Textures are applied to a mesh by unwrapping said mesh onto the 2D image. If you could transfer this mapping to paper, why not do the opposite to recreate your 3D model in the real world?
Here's an example of how the process works. The following was done in Blender and Photoshop, and you can switch that out with the Gimp or forgo the editing step altogether like a boss.
[B]
The model[/B]
The first step is to make a 3D model. If you can't visualize space all that well, keep it simple. I chose a chair.
[IMG]http://i52.tinypic.com/2cdydqg.png[/IMG]
This model is obviously on the simple side, but too much detail would shrink it below a comfortable size for gluing and fiddling with. If you have other means of outputting the image on larger or thicker paper, however, these restrictions don't apply.
[B]Unwrapping the mesh
[/B]Unfortunately, this step is best left to the user. You want to make sure that the model is as sturdy as possible, so you'll need to unwrap the mesh so that the longest adjacent edges remain connected. These instructions are specific to Blender.
[IMG]http://i56.tinypic.com/20ieved.png[/IMG]
In Blender (and probably most other 3D tools), UV unwrapping is dependent on user-defined rips called seams. These seams are treated as the cutting points before unfolding, since most meshes cannot be unfolded as they are without such holes. This is a rather difficult part, because it's up to you to decide where to put the seams to most efficiently unwrap your model, preferably in one piece. Still, it's a step up from drawing up the plans from scratch, since the layout will basically be created for you once you're done. Also, create an image with about the same proportions as the paper you'll print on and have it open in the UV image editor.
[IMG]http://i52.tinypic.com/24w53jm.png[/IMG]
In Blender, you'll want to change the method of unwrap to "conformal" and disable "fill holes" in the tool panel (T key) after unwrapping the mesh (U key). This will ensure that the mesh is unwrapped rigidly and not organically, with stretching and scaling. If you failed to keep the mesh in one piece (it's not always possible), you'll need to make sure the UV islands are all the right size relative to each other. In the UV image editor, select all UV's and hit ctrl-A to average the islands' scale. Then hit ctrl-P to pack islands, making efficient use of space. My model was in one piece, so here's the UV layout:
[IMG]http://i54.tinypic.com/2rnaa2r.png[/IMG]
[B]
Touching up the image[/B]
You could just export the UV layout and print it as is, but I did a bit of fine tuning. Firstly, simply exporting your UV layout will include a lot of useless edges that make up flat surfaces, which will only confuse you on paper. The best way to quickly distinguish different-facing faces in your mesh is to bake the normals into your image.
[IMG]http://i52.tinypic.com/w1v42c.png[/IMG]
Make sure the margin is set to 0 to prevent color bleeding, and have the type of normal set to global or it will all just turn purple. If you have it mapped to an image, the faces of your mesh should all get colored so that all distinctly angled surfaces are different colors. My chair generated this map:
[IMG]http://i55.tinypic.com/28qr95t.png[/IMG]
You can edit this image in any program, or just print it now (though you will have to remember where to fold as opposed to cut). I used an edge detect filter to get rid of the colors and save ink, leaving only the essential lines and changing fold lines to dotted lines. Tabs are also an important factor in stabilizing your model, unless you use tape; you can add these as well.
[IMG]http://i56.tinypic.com/2lpbt3.png[/IMG]
[B]Construction[/B]
With all that planning out of the way, you should now have a guide to follow, ideally one which tells you where to cut, where to fold, and how to fold (concave or convex). It might get really confusing otherwise, and probably still is. Nevertheless, here's the finished product in its simple glory.
[IMG]http://i55.tinypic.com/dr5r29.jpg[/IMG]
It matches up pretty well with the model, as I have seen by holding it up to the screen and rotating both the prototype and its child simultaneously while grinning like an idiot.
[B]Tips
[/B]For concave holes like the one in my chair's back, you can have every other interior face connected to one of the two holes (on each side of the one hole). This allows the faces to remain connected to the body without overlapping in the layout, interlocking to form a continuous surface.
Don't start gluing before you've cut/folded everything... shit will get messy.
If your mesh has a significant number of parts, number or label your tabs somehow.
_____
I was actually amazed that the legs ended up straight, considering that I had them feed into a base with four flimsy holes. All this can now be done without excessive measurements and trigonometry, thanks to space-age technology (which falls only a bit short of 3D printing technology), while preserving the human element in the resulting creations; no automated process is as practical as the human mind in laying out a creation with regard to its form, leaving a natural beauty in the imperfect fragility of something created with an imprint of the human mind rather than incremental layers of plastic. Unless you decide to make something stupid like a chair.
Fucking amazing
Recommended you for a highlight in the Ask Me about the Forums. Great guide, I should definitely try this.
papercraft is cool but it doesn't work well for anything complex unless you have enough adderall for a year
[QUOTE=DOG-GY;31147329]papercraft is cool but it doesn't work well for anything complex unless you have enough adderall for a year[/QUOTE]
There are people whose sole joy in life is gluing together Millennium Falcons. I think as long as you use multiple sheets, you can add plenty of detail without having to use a microscope.
There's a program that already does this pretty simply without 3DS Max, as long as you have a relatively simple 3D model (though I have seen it done with complicated meshes before).
[url]http://www.tamasoft.co.jp/pepakura-en/[/url]
[QUOTE=RiceWarrior;31151450]There's a program that already does this pretty simply without 3DS Max, as long as you have a relatively simple 3D model (though I have seen it done with complicated meshes before).
[url]http://www.tamasoft.co.jp/pepakura-en/[/url][/QUOTE]
He used Blender.
[QUOTE=ShnitzelKiller;31148043]There are people whose sole joy in life is gluing together Millennium Falcons. I think as long as you use multiple sheets, you can add plenty of detail without having to use a microscope.[/QUOTE]
I on the other hand enjoy going outside more than once a month.
[QUOTE=DOG-GY;31155021]I on the other hand enjoy going outside more than once a month.[/QUOTE]
you seem to have some sort of grudge, don't know what else to tell you.
[QUOTE=RiceWarrior;31151450]There's a program that already does this pretty simply without 3DS Max, as long as you have a relatively simple 3D model (though I have seen it done with complicated meshes before).
[url]http://www.tamasoft.co.jp/pepakura-en/[/url][/QUOTE]
When they say that export functions are disabled in the free version, do they mean it somehow prevents you from grabbing the layout via snapshot?
[editline]16th July 2011[/editline]
Oh wait I'd have to buy max and then buy this plugin.
[QUOTE=ShnitzelKiller;31156170]you seem to have some sort of grudge, don't know what else to tell you.[/QUOTE]
yes I have a grudge against papercraft
???
I know how to model but I have no idea what you're talking about
[QUOTE=DOG-GY;31155021]I on the other hand enjoy going outside more than once a month.[/QUOTE]
God forbid someone has a hobby they enjoy.
Awesome! I deff will try this.
I can see this being abused very easily.
in the form of papercraft penises
*crush*
[QUOTE=Sifflix;31234239]God forbid someone has a hobby they enjoy.[/QUOTE]
holy FUCK way to misinterpret that
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