Hi all.

I'm messing with an idea that calls for redrawing tracing lines according to a new shape.

For instance, let's say you have a ball (a sphere), but you want to take a section of the surface of that sphere and draw or “trace” a pattern of vector lines in that section on the sphere. Once you have this, let's say you resize that section (make it bigger or a slightly different shape). I want the resizing to cause the trace sop (function) to “redraw” or adjust the tracing to fit the new resized shape.

Does anyone have any info on this?


Thanks!

moreguns
For instance, let's say you have a ball (a sphere), but you want to take a section of the surface of that sphere and draw or “trace” a pattern of vector lines in that section on the sphere. Once you have this, let's say you resize that section (make it bigger or a slightly different shape). I want the resizing to cause the trace sop (function) to “redraw” or adjust the tracing to fit the new resized shape.

Well, it depends on how you transfer your trace to the sphere. Houdini will recook the SOP chain whenever something changes. Thus if your sphere changes, things should recook automatically.

That being said, there are a couple of ways to get a tracing onto a sphere. You could use a ray SOP to ray the resulting trace lines onto the sphere. Or you could (if you have a NURBS surface, e.g.) use the TX and TY as MAPU and MAPV to project onto the surface. The project SOP might also be helpful.

You could also use a creep sop to get the tracing onto the sphere, that will create a distortion but you might be able to correct for that before the creep sop is applied.