Texture mapping incorrect for 3ds export

godsilla · 14 Jun 2008, 00:19

I am working on a java application that renders a 3ds model. I have found many nice models in the sketchup warehouse. I am testing my application with this one:

http://sketchup.google.com/3dwarehouse/details?mid=51788177a9c83dd31eceb74c5cae6556&prevstart=0
(Go A's)

My export options are Full hierarchy, export stand alone edges, export texture maps with preserving texture coordinates. i'm also generating cameras from pages and the scale is model units.

I can parse the 3ds file correctly, but i get a problem when i get to the 0x4140 block. this is supposed to be a list of pairs of texturing mapping amounts with the values being between 0 and 1. many of the values i've found for some of the chunks are considerably outside of that range. the result is that that texture doesn't get correctly mapped to the surface. (if you don't understand this paragraph, that's fine).

so my question is the following: is my parser incorrect, or is the export from sketchup broken? i've read a lot of posts noting that people are having problems with the texture mapping when they export to 3ds.

i would be greatly appreciative if somebody could take the model i noted above, convert it to 3ds and then show me a screenshot in 3d max showing the correct rendering. also, please advise SPECIFICALLY what you did to export it from sketch up.

also, let me know if you are unable to view the correct textures in max. that would help me isolate my problem.

thanks for your help! ohh ... i'm running sketch up 6.

Alan Fraser · 14 Jun 2008, 07:00

I got this result in Max from the export, which seems to be pretty close to the original. As with all 3ds exports from SU, you can use the export options to have the vertices welded, preserving smooth curves or you can retain the mapping coordinates. Very rarely can you get both.

godsilla · 14 Jun 2008, 18:43

yes, that does look pretty right on. can you tell me exactly how you exported the file to 3ds? i'm kind of a beginner here and don't fully understand all the concepts.

Alan Fraser · 14 Jun 2008, 18:51

Just go to File > Export > 3ds....but then notice the Options button hiding in plain sight on the export dialog box. By default it's probably set to weld vertices. You'll need to change it to Preserve Texture coordinates.