Blender render and Shapeways render not in agreement

Discussion in 'Design and Modeling' started by bvr, Feb 27, 2012.

  1. bvr
    bvr Member
    Hello everyone,
    Perhaps someone can help me out, I just don't know what else to try.
    I have what I thought was going to be a simple thing...wow, was I wrong.
    I have made a hollow sphere I would like to print with an image on it and back-light it.

    First I created my model with Hexagon. Model passes manifold and normal checks. I upload it and it renders correctly. The volume and pricing are correct. I am assuming my basic mesh is ok.

    I tried to UV map with Blender 2.49 and worked through finding out it does not work quite right. Upon multiple people recommending the newest, I started over with Blender 2.61

    After reading more than a few forum posts and watching a few tutorial videos I can fumble through Blender. I selected all the external faces and unwrapped them. Added my image, added a material then a texture. Scaled and positioned the uv map on my image. Everything looks good here,(because i did not know to actually render at that point, I was just viewing the textured viewport) Upload to Shapeways and in the render it now has the image on the outside as it should..but, it now has the image in full applied to every face I did not unwrap(every interior face). This is no good, as I am going to back-light it and it will show/degrade the lighting.

    After a bit of searching I find a post that seems to deal with just this problem.
    Yep it sure does, just not for printing. That method turned my hollow solid. Even though it looked ok in the render, the volume and price were for a solid.

    OK, more searching and I find the post I was looking for and I'm pretty sure I followed what was being said.
    (from a blender forum)
    "Remember that you cannot unwrap just part of the mesh. If you add a UV Map either with the U key or from the UV Maps panel it applies uv coordinates to every face of your object. Any face that you didn't select when unwrapped would just have the default coordinates, each face mapped to the full UV area. If you don't want a texture applied to those faces just select the faces and drag them outside the UV area and set the texture Image Mapping to Clip. Or just drag the faces to a blank area of the texture. "

    That explains what was happening when I was just unwrapping the outside.

    I worked my way through this method. I did a second unwrap on the interior faces, dragged them outside the image area, set the image to clip. I get a perfect render(actual render), great.

    I upload to Shapeways, volume and pricing are correct and I have my image on the outside, BUT, the image is now mapped to the inside too! The whole image, not tiled on each face.
    I re-rendered the file here and Blender renders it correctly(i put a camera and light inside to check for sure). So now I am really confused.

    If I had known what I was going to undertake(such a simple thing, right?)I probably would've paid someone to create the blend files. Now I just want that "ah-ha" moment. And I need two iterations of it, so I should learn how to do it.

    Does anyone have any insight?

    thank you
    bvr
     
  2. If you applied the texture in the UV map editor there is a slight problem. It needs to be reopened as a image texture, and applied to UV mapping to the objects material.
    The blank space comment concerns after you properly unwrap the outer faces, export uv layout/image paint,create the texture, you can then select all faces, uv unwrap how ever you want, scale the verts in the UV editor, then move them to a solid colored part of the texture image you originally created. Then unwrap the exterior faces, as you did to export, apply image texture again. It should be a perfect fit. Then just apply it as a image texture, uv mapping.
    This takes some practice, if you need help, go to irc..Freenode.net, channels blender or blenderchat
     
  3. bvr
    bvr Member
    Fredd,
    The image was first opened in the uv editor, then it was set for the texture via the open button in the textures panel. I've spent the last week digging through the blender forums. I have blender rendering correctly. Shapeways isnt now.
    bvr
     
    Last edited: Feb 28, 2012
  4. bartv
    bartv Member
    What happens if you watch the exported file in a tool like MeshLab? Will it show the texture on the inside as well, or not?

    Bart
     
  5. bvr
    bvr Member
    Bart,
    I cannot run meshlab :cry:
    bvr
     
  6. Mswlik
    Mswlik Active Member
    Have you tried going to the textures tab in the properties window and changing to generated to UV under mapping? If you already have I would suggest creating a new material and assigning it to the inside of the object.
     
  7. bartv
    bartv Member
    Why not? It's available for Windows, OSX and Linux..

    I found that displaying a model in MeshLab gives a pretty good prediction of how it will upload on Shapeways.

    Bart
     
  8. bvr
    bvr Member
    Thanks again everyone. It seems that Shapeways renderer handles uv maps differently from my installation of blender.

    I believe I have managed to find a solution whereby both my install of blender and the shapeways render coincide. It's somewhat of a cheat, but it works.

    The pertinent question now is in regards to the actual print process. Is the process CMYK? How will it interpret the "color" white?

    bvr
     
  9. bvr
    bvr Member
    Mswlik,
    Your suggestion of another material surely would've corrected the problem. It didnt occur to me that trying to print no color on everything else would be an issue with one material. It still seems odd, but i have found a cheat that works with just one material.--I hope it works--$90 to find out.
    bvr
     
  10. Youknowwho4eva
    Youknowwho4eva Well-Known Member
    Everytime I have seen Shapeways handle a uv map differently, it's be overlapping faces. When the software sees two faces taking up the same space, it deletes one, therefor modifying the uv map coordinates. So parts can't sit face to face. They can however be inside each other as long as faces don't overlap. And you won't be charged twice for the overlapping geometry.
     
  11. Hello I am new to textures and blender and you guys seem to know what your doing I am having a problem with my textures appearing correctly in the shape ways render and I think it might be overlapping faces so I was wondering if anyone could tell me how to fix them (overlapping faces)
     
  12. Mswlik
    Mswlik Active Member
    if there are ovelapping faces then when you select one face and hit ctrl L it will select either all of the faces that are overlaping or all of the ones that are not depending on where you click. If it selects the faces you want to keep hit ctrl I and it will select all of the faces that are unselected and deselect the faces that are. You can then delete the faces you don't want by pressing ctrl X. Hope I helped.
     
    Last edited: Jun 26, 2012