   Multitexture and Vertex Blending with Vertex Programs
  Right then. I''ve barely done any stuff with vertex programs (apart from basic transformations), but I''ve had the idea to try vertex blending with it (seeing as nVidia dropped the EXT_vertex_weighting extension and doesn''t support ARB_vertex_blend yes).The only way I can see of getting my vertex co-ords to the program is by using up another texture unit (fortunatly i''m using 3 at the moment with a geforce4ti, so i''ve got one left) and pass them as 3D texture co-ordinates.Once i''ve passed the 3 texture-coordinates to the vertex program output along with the blended vertex, i''m left with the final texture slot which is waiting for some texture co-ordinates. Obviously, I don''t have some.so, what i''m looking for is a way to input 4 texture co-ordinates to the vertex program and output 3 (0, 1, 2) and disable the 4th unit.Possible solutions:1) disable texturing on the 4th unitnot sure if this would block the second set of vertex positions to the vertex shader).2) bind texture zero to the 4th unitwould have to pass 0, 0, 0 for the 4th texture unit in the vertex program. Might add another texture stage in the fragment processing.3) ask you lot for helpwill most probably get the correct answer. best solution or, if you know of any plans to put ARB_vertex_blend on the geforce4ti let me know and i''ll postpone vertex blending until then 
  Using Vertex Program, you specify Vertex Attributes via :glEnableVertexAttribArrayARB and glVertexAttribPointerARBSo you don''t need to use a Texture Unit at all.Just feed VertexAttrib x with the data, and access it from the VP. -* So many things to do, so little time to spend. *-;quote:Original post by Ingenu  Using Vertex Program, you specify Vertex Attributes via :glEnableVertexAttribArrayARB and glVertexAttribPointerARBSo you don''t need to use a Texture Unit at all.Just feed VertexAttrib x with the data, and access it from the VP. -* So many things to do, so little time to spend. *- thanks, i always wondered what vertex attribs were used for 