I need help on mapping an image, Is it triangles? Quads?

http://mysite.verizon.net/vze3nvj6/Blender/forum/mapping.jpg

The image above shows 2 pillar crowns. The one on the left is entirely created from triangles. The one on the right is actually the one on the left, but modified a bit by removing the triangles and replacing them with quads (the primary vertices & coordinates are untouched).

Now, here’s what is bizarre to me. The one on the left mysteriously accepts a material perfectly, no unwrapping or and special adjustments. The one on the right has the same settings, yet the material is all screwed up?

How do I make the one on the right look like the one on the left, but keep the quads?


And if you are curious about the original mesh (and JPEG maps), you can download that at…
http://hdri.cgtechniques.com/~sponza/files/ Choose the 3DS file then import that into Blender with the special script called 3DS Importer v0.83 here…
http://members.iinet.net.au/~cpbarton/ideasman/

no sure, but do yu have TexFace enabled?

NO, it is not needed. I tried it and there is no difference. I have been uvmapping, textureing, multi-texturing, materials, etc… for a lot of projects and this is the first time I have came across this problem.

It almost seems like there may be a button that is “global”, kind of like creating a 3D level in “Unreal Tournament-99” and making all of the meshes lign up with the material. I don’t know.

Basically, I am re-meshing that Sponza project, to make it more Blender Render friendly. There are tens of thousands of duplicated vertices and triangles that seem to be wasting resources. Overlapping lines. It is a total mess when imported from 3Ds (in my opinion).

How are you joining triangles? Even with ALT J (which has no respect for uv map islands) you shouldn’t get the results you are getting.

Go to the same site where you downloaded the 3DS importer and get the triangles to quads script (if it is not already installed by as standard). Import your object, remove doubles and run that script for every object. It will take a very very long time (be patient) but you will get better results.

I already tried with the files your link to, I had no problem at all. (IMAGE)

tolobán --> Your example looks like it shows only one pillar crown. There’s about a dozen more that have to do exactly the same thing.

Here’s what I found out.

If you create one of those pillar crowns, and go to UVmode, you can press the U-Key and select “Bounds 1/1”. Then you most likely have to manually move and adjust each face precisely for the JPEG image.

Now, go back to EDIT (not objedt) mode and Shift+D the mesh to complete the rest of the pillar crowns.

If you go into UVMode again, you’ll see that the other sections of the mesh are exactly the same. The UV Image Editor will show that the faces are exactly on top of each other too. So if you place a JPEG on one, it affect all of them in the same manner.

I find it amazing that the original Sponza Mesh was exported from viz3, then to 3DS, then into Blender, and yet still retains UVmapping and even some vertice groups for the materials.

The 3DS import script had some recent updating. Maybe previously it didn’t import UV maps and image textures, but now it does. That is good news (and this solves your import mystery ;)):
https://blenderartists.org/forum/viewtopic.php?t=48490&highlight=3ds+import+script

Every polygon or face in the 3D mesh has a counterpart 2D polygon in a UV map. This UV face can be assigned to one or no image and can be located anywhere relative to the rectangular placeholder which an image can fill.

If you try to simplify a mesh which already has UV textures you must use a tool which will will preserve the uv mapping. If you delete any face you will delete also its mapping, because the UV face also disappears. You can’t expect Blender to create a quad where two triangles used to be and guess it should use the mapping the lost triangles had.

These are your basic tools:

  • ALT + J: joins two triangles as long as they make a convex quad. It updates the UV map. However two triangles sharing an edge in the mesh not necesarily share an edge in the UV map, so if those triangles are in different UV islands the result can mess up the UV map.

This shortcut very often does a bad job if you select many vertices, joining triangles which shouldn’t be joined. That is why I prefer the tris to quads script.

  • CTRL + T: The opposite, converts quads to triangles. You might want to do this if you can make a better arrangement joining with neighboring triangles.

  • CTRL + F: Flip an edge. Select two triangles and flip the common edge. Also useful sometimes to better arrange triangles to be joined as quads.

  • ALT + M: Merge vertices. Avoid using this one, this is a texture destroyer, simply doesn’t care to update UV maps.

I know there is one pillar crown in my image, all others are out of sight because of perspective but I didn’t delete them or anything. Since the importer loads the 3DS file as various objects I went in local mode for the object containing the crowns (PADSLASH key) that’s why all other objects are hidden.

As I wrote before, I just loaded the 3DS object, removed doubles and joined some triangles.

I think you need a bit of reading about UV mapping. This is a start:
http://www.blender3d.org/documentation/htmlI/x5138.html

Thanks a lot! I am impressed with the importer script. As far as the UVmapping, I have a pretty good bit of understanding how to use it.

And the Sponza project, I am still having fun with it. I’ll probably make my next project with stone and brick, also design the UVmapping with vertices in mind, so that they do overlap in the UV Editor.

Ok Spin, very nice work your room image . :o

ur right clownny!!!

The original Sponza was done in Lightwave. Does the LW import script support UV’s? The scene is comprised mostly of quads and might save you some time. 1729 n-gons, 33208 quads, and 2373 tris. Looks like the tris are mostly for fan shapes or cylinder caps.

feh, never mind. Lightwave is lame, LW importer is lame. I give up and walk away. :slight_smile: fwiw here’s a cob version. I think the UV’s are missing.
sponza_test6_sve_cob.zip