UV coords size
Blitz3D Forums/Blitz3D Beginners Area/UV coords size
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| Hello, It is possible to use more than 2 UVcoords per vertex (i mean UVcoords not UVsets)? For example: i have quadpolygon (2 triangles), one texture and i need to texture every triangle individually. How can i do that without duplication of vertices? |
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| You can't. Even if you could have more than one UV coord per vertex, how would the renderer know which coords to use for any given triangle that vertex may be part of? The only way to do what you want is to duplicate vertices. |
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| Thanks for answer. Very baaad... and strange. Specification-file ("b3dfile_specs.txt") tells: "[...] VRTS: [...] int tex_coord_sets ;texture coords per vertex (eg: 1 for simple U/V) max=8 int tex_coord_set_size ;components per set (eg: 2 for simple U/V) max=4 [...] ", but we can't use that from Blitz. :( |
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| errm, I must confess to not having tried more than two, but I don't understand big10p's response about not knowing what coords to use.... that info is taken from the texture being applied, as in what coordset to use, based upon the surface it is being applied to, surely?? Anyway it may be a bit long winded but I'd try a simple test program to see what you get. I'd be interested in results. My thoughts are though that 2 may be the limit, but I think this is because of wanting b3d to be compatible with older 3d cards, but what do I know ;D |
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| Yes B3D has 2 UV coord sets but they're used to apply 2 or more separate textures to a surface. Mikele - as I understand him - wants to individually texture connected triangles using a single texture. This can't be done without unwelding all the triangles. Thanks for answer. Very baaad... and strange. Specification-file ("b3dfile_specs.txt") tells: "[...] VRTS: [...] int tex_coord_sets ;texture coords per vertex (eg: 1 for simple U/V) max=8 int tex_coord_set_size ;components per set (eg: 2 for simple U/V) max=4 [...] ", but we can't use that from Blitz. :( Not strange to me. I don't confess to know anything about the B3D file format but that info seems to say: - it supports upto 8 UV sets (currently only 2 are implemented). - each set can have upto 4 coords (currently only the U and V coords are implemented. The W coord is partially implemented but not used. That's 3 altogether with, apparently, room for 1 more.) |
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| Nothing strange about it. Rendering 3D graphics always requires duplicate vertices for each UV coordinate, vertex normal, etc. Some renderers automate the duplication so that as far as the user is concerned it appears to be one vertex, but duplication is definitely happening, and you have no control since it is automated. |
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