1
$\begingroup$

I am using Blender version 2.74 and I am using an OpenSCAD file someone else made. I am new to Blender.

The OpenSCAD file comes from this website: http://kitwallace.co.uk/3d/solid-to-scad.xq?id=Tetrahedron&scad=shell I picked "engrave" for the OpenSCAD option.

I am trying to create UV coordinates for the shape after I import the OpenSCAD file in Blender, so that I can dynamically display a unique image on each face of the tetrahedron as an exported or "finished" JSON file using JavaScript. Whether I export into whatever format using some type of technology such as JavaScript - I don't know if that part is relevant. But the question I have is how to compute/make the UV coordinates for this shape in Blender to make this eventually happen.

Below is the JSON file, the blend file couldn't be shown in text format:

{
    "name": "Tetrahedron.001Geometry",
    "uvs": [],
    "faces": [32,0,1,2,0,1,2,32,3,2,1,3,2,1,32,3,0,2,3,0,2,32,3,1,0,3,1,0],
    "vertices": [-2.42416,0,4.19877,-2.42416,-0,-4.19877,4.84832,0,-0,-0,6.85655,-0],
    "metadata": {
        "type": "Geometry",
        "version": 3,
        "vertices": 4,
        "generator": "io_three",
        "faces": 4,
        "uvs": 0,
        "normals": 4
    },
    "normals": [-0.471389,-0.333323,0.816492,-0.471389,-0.333323,-0.816492,0.942808,-0.333323,0,0,1,0]
}

$\endgroup$
  • $\begingroup$ Have you searched the site⸮ See this question $\endgroup$ – someonewithpc Jul 31 '15 at 14:04
  • $\begingroup$ Can each face be UV mapped separately or do you need to keep the mesh unwrapped as one joined uv island via seams? $\endgroup$ – Todd McIntosh Jul 31 '15 at 14:34
  • $\begingroup$ If the file import is not the issue, perhaps post the blend of the already imported tetrahedron mesh object. $\endgroup$ – Todd McIntosh Jul 31 '15 at 14:36
  • $\begingroup$ { "name": "Tetrahedron.001Geometry", "uvs": [], "faces": [32,0,1,2,0,1,2,32,3,2,1,3,2,1,32,3,0,2,3,0,2,32,3,1,0,3,1,0], "vertices": [-2.42416,0,4.19877,-2.42416,-0,-4.19877,4.84832,0,-0,-0,6.85655,-0], "metadata": { "type": "Geometry", "version": 3, "vertices": 4, "generator": "io_three", "faces": 4, "uvs": 0, "normals": 4 }, "normals": [-0.471389,-0.333323,0.816492,-0.471389,-0.333323,-0.816492,0.942808,-0.333323,0,0,1,0] } $\endgroup$ – ACoder Jul 31 '15 at 14:58
  • $\begingroup$ The JSON won't really help us. You'll have to upload the blend file elsewhere and post a link. This is a good option: blend-exchange.giantcowfilms.com $\endgroup$ – Todd McIntosh Jul 31 '15 at 15:02
1
$\begingroup$

You can unwrap the tetrahedron in one of 2 ways:

  1. You can create seams (CTRL+E > Mark Seams) running along the 3 edges from the base to the tip. Then select all vertices and press U > UV Unwrap.

enter image description here enter image description here

  1. You can create seams on all edges (CTRL+E >Mark Seams) , and overlay each uv island on top of itself. Then select all vertices and press U > UV Unwrap.

enter image description here enter image description here

Please note the tetrahedron shape in my example is an approximate shape only in order to demonstrate the unwrap technique.

|improve this answer|||||
$\endgroup$
  • $\begingroup$ How do I create seams in Blender? What is the purpose of creating seams - sorry I just don't know much about this. $\endgroup$ – ACoder Jul 31 '15 at 15:13
  • $\begingroup$ @ACoder Select the edge(s), Ctrl + E > Mark Seam $\endgroup$ – p2or Jul 31 '15 at 15:20
  • $\begingroup$ Updated my answer to include mark seam command. $\endgroup$ – Todd McIntosh Jul 31 '15 at 16:43
  • $\begingroup$ Adding seams is just like seams in a fabric pattern for a piece of clothing. If you want all the faces to be connected in the UV map, they can't be connected on every side to unwrap flat and undistorted. $\endgroup$ – Todd McIntosh Jul 31 '15 at 16:46
  • $\begingroup$ Thank your for your ongoing explanation and procedures in doing so. I do have a question about 2nd way of unwrapping the tetrahedron. You said to select all edges and mark the seams on those, and it was the second part of that sentence I had a question about: overlay each uv island on top of itself. I'm unclear on how to do that. What or how do I do that? Sorry for the constant questions - I'm just curious. $\endgroup$ – ACoder Jul 31 '15 at 18:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.