doodlemunch

01-12-2006, 08:05 AM

wat is the teory behind texture mapping a torus???

how should i proceed?

any formula?

thx

how should i proceed?

any formula?

thx

View Full Version : torus uv mapping need help!!

doodlemunch

01-12-2006, 08:05 AM

wat is the teory behind texture mapping a torus???

how should i proceed?

any formula?

thx

how should i proceed?

any formula?

thx

dorbie

01-12-2006, 08:18 AM

It's quite simple. Each point on a torus can be described by two angles. The first angle is that of the major ring around the center of the torus. The second angle is the angle around the minor circle extruded or swept around the major ring.

So for each vertex the texture coordinate would be s = major angle t = minor angle, multiply the angle by some factor like 1/360 for degrees or 0.5/PI for radians. You may want to repeat the mapping along the major axis.

At the seam the vertex is duplicated with a different texture coordinate for angle = 0 degrees and angle = 360 degrees, the vertex location for these angles will be the same given the math to calculate the point on the torus. If you scale teh coordinates by a number that produces a round multiple of 1.0 for 360 degrees then the texture will appear seamless.

So for each vertex the texture coordinate would be s = major angle t = minor angle, multiply the angle by some factor like 1/360 for degrees or 0.5/PI for radians. You may want to repeat the mapping along the major axis.

At the seam the vertex is duplicated with a different texture coordinate for angle = 0 degrees and angle = 360 degrees, the vertex location for these angles will be the same given the math to calculate the point on the torus. If you scale teh coordinates by a number that produces a round multiple of 1.0 for 360 degrees then the texture will appear seamless.

doodlemunch

01-12-2006, 06:31 PM

uh i tried it did not worket as i espectet it to

it looks funny the textur!

it looks funny the textur!

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