Tessellation Pattern

[aspect]

hi all,

I want to create some tessellation pattern on surfaces. Examples like this here- http://farm3.static.flickr.com/2407/204959...c628e9833_o.jpg

Wonder if I create some line patterns, then what Sops can project lines onto surfaces and become part of the tessellation configurations?

Or say if I have a square grid and a circle grid, how do I fuse the two pattern together and become as one tessellation configurations? (I did use the "merge" then "fuse", but two grids only shown as overlapping each other and not as one grid with "fused" pattern.

Thanks.

[kleer001]

That pattern looks like circles that are repeted along a grid, the circles' radii increase from left to right and top to bottom. It also looks like the picture is about 50x25 points on the grid.

1 - start a new houdini

2 - greate a geo sop

3 - go into the geo sop

4 - delete the default file sop

5 - create a grid sop

6 - damn... this is going to take longer to describe than just do...

Here's the file attached and image.

Take note of the stamp expression in the circle's transform node and the added stamp attributes in the copy sop. That's where the magic happens.

Now, if you're trying to do this with a shader, man, that's a whole new ball of wax.

circleTesselation.hip

[aspect]

That pattern looks like circles that are repeted along a grid, the circles' radii increase from left to right and top to bottom. It also looks like the picture is about 50x25 points on the grid.

1 - start a new houdini

2 - greate a geo sop

3 - go into the geo sop

4 - delete the default file sop

5 - create a grid sop

6 - damn... this is going to take longer to describe than just do...

Here's the file attached and image.

Take note of the stamp expression in the circle's transform node and the added stamp attributes in the copy sop. That's where the magic happens.

Now, if you're trying to do this with a shader, man, that's a whole new ball of wax.

hi kleer, wow! that is great! wonder how some ppl can do it so easily... say if i want to do a pattern like this in vex, how to project the lines onto the surface as a tessellation pattern? possible in houdini?

many thanks!

[kleer001]

in vex? I have no idea. I say render it out and use it as a file texture. Render it out in Greyscale then you can change its color in the shader.

hi kleer, wow! that is great! wonder how some ppl can do it so easily... say if i want to do a pattern like this in vex, how to project the lines onto the surface as a tessellation pattern? possible in houdini?

many thanks!

[doc]

hi kleer, wow! that is great! wonder how some ppl can do it so easily... say if i want to do a pattern like this in vex, how to project the lines onto the surface as a tessellation pattern? possible in houdini?

many thanks!

You could certainly do it with vex via a procedural shader.

if you have a look at:rman notes : circle pattern

this should give you an idea on how to create a basic circle. the code is in RSL so it may take a little converting to get it in to

vex, but it's totally doable.

form there you'll have to convert kleer's sop net into vex code.

Here's the way I'd approach it:

1) the copy sop is basically like a for loop, so use a for loop (or acouple of for loops one for x direction and one for y) in your vex code to make several copies of the ring from rman notes .

2) the other issue is that Kleer is using a template to copy his circles to, you won't have this option in your vex code.

What you can do use your for loop(s) to offset your circles in uv space.

of course there's a lot more step involved , but that should flesh out the broad strokes.

hope that helps.

L