Re: [Algorithms] Texture mapping, Weighted Vertex Normals and Octree Nodes

[Juan C. A. B. <jc...@ro...>]

At 12:07 PM 1/29/2001 +1100, you wrote:

>Texture Mapping:
>Just say I have a stone. The stone is roughly spherical(convex). I have a 
>texture that has been made tileable and would like to wrap the stone in 
>the texture without seams. This concept seems quite difficult for me 
>without the use of some bizzare shape dependent use of spherical mapping 
>and modifying the texture. How does one do this?

    If the texture is made tileable in such a way that a horizontal edge 
matches a vertical edge, then you can make a cube, texture it, and then 
inflate it to make it spherical in shape.

    If horizontal edges do not match vertical edges, I believe that you can 
do it with a tetrahedron instead of a cube. The math is a bit more complex, 
though. The tetrahedron has 4 triangle faces, so you just pair them two and 
two, which gives you two squares for mapping the texture.


    Salutaciones,
                               JCAB

---------------------------------------------------------------------
Juan Carlos "JCAB" Arevalo Baeza    | http://www.roningames.com
Senior Technology programmer        | mailto:jc...@ro...
Ronin Entertainment                 | ICQ: 10913692
                        (my opinions are only mine)
JCAB's Rumblings: http://www.metro.net/jcab/Rumblings/html/index.html