Create Polygon Meshes from Instance Shapes

[guillaume]

Hi,

After reading some discussions on the Softimage mailing list on how to generate a polygon mesh from a point cloud using some shape instances (with UVs and material preservation), I started to work on new ICE compound. Here is a little video showing the workflow :

http://dl.dropbox.com/u/5533643/Softima ... eShape.swf.

It gives you the ability to copy several polygon mesh into a new one using a particle point cloud. For example, you could have two or three base meshes and randomly distribute them on each particles of a point cloud. Here is a sample scene and the compound :

http://dl.dropbox.com/u/5533643/Softima ... eShape.rar

I just test it on very simple things, so let me know if it works for you !

Cheers,

Guillaume Laforge

[guillaume]

I just found the first bug .

If one of your source meshes topology is edited after you apply a texture projection on it (lets call it a "Post UV split mesh", its copies could get wrong UVs. I already get the same problem when I designed the "Clone Polygon Mesh" compound for 2012. This is because Softimage keep polynode index unique. For example if you apply a texture projection on a mesh, and then split a polygon, its existing polynodes indices will stay the same. But if you rebuild a new mesh using the polygon description of the splited mesh, the polynodes won't be ordered in the same order (as polynodes indices are implicitly computed from the vertices and polygons orders). For the "Clone Polygon Mesh", I found a way to get it working even on those "Post UV split mesh" by getting the polynodes indices from the polygons instead of directly accessing their indices.
So, it should be possible to support "Post UV split mesh" on the new "Create Polygon Meshes from Instance Shapes" too. Btw, I don't know when I will get a chance to look at it.
In the meantime, if you've got this kind of UVs problems, the workaround is to extract all the polygons of your source meshes and use this extracted version instead (The "Extract Polygons" operator will re-order the polynodes in the implicit order for you).

Guillaume

[Matic]

Wow! This is one of the most useful ICE compounds ever! Thank you!

[rray]

Indeed. Thanks Guillaume.

[Sandy_S]

I am guessing this is a 2012 thing only - scene does not load here - we are still on 2011 sap SP1!!

[guillaume]

I am guessing this is a 2012 thing only - scene does not load here - we are still on 2011 sap SP1!!

Yes it is 2012 only as it is using new ICE Topology nodes.

[Sandy_S]

Thanks - out of interest, is it possible to export the mesh this generates as an obj .xsi etc... - maybe we can get a 2012 going to use it and revert the asset backwards??

Cheers

S.

[Victorcg]

I get the resulting polymesh scaled maybe twice larger, than original PC. Any suggestions?

[Pancho]

I urgently need to export a particle animation in which I replace the particles with a simple polygon. So this node seemed to be my life saver.

But unfortunately I don't get it to work. I'm running 2012.

What became an issue first is the material ID and material ID sources nodes. No idea how to get these to work. So I disconnected them to avoid the red not working nodes. I just need simple polygons instanced. No material or anything applied.

After finding out that I need to apply a UV texture to make this compound happy, that's something I couldn't figure out apart from disconnecting the material id branches.

BUT WHAT STILL DOESN'T WORK IS THE TOPOLOGY NODE!!!

In the create topology compound the last node "Set Topology" stays red. How do I get it to work!?!?!?

Some help would be highly appreciated! In case I can't export these polys, could somebody point out a solution? Just plain polys instead of particles (simple quad poly).

Thanks in advance! I'm really stuck right now!

Cheers
Thomas

[Pancho]

O.k., needed to move the ICE tree into the modelling stack. Now the compound seems to generate the polys correctly, but as soon as I stop at a frame to try to export it the just generated polygons dissappear apart from those just "born" on the emitter.

How do I keep the already spawned polys?

[Pancho]

Seems to work now if I export it as an obj., point oven .lwo didnt.

Sorry for the hassle, but I'm a bit under pressure currently.

Thanks!

[Pancho]

Mmmmh. I managed to stop the animation once and export it as an obj.

But afterwards everything failed. Either the just created ICE geometry disappeared or didn't export at all. For the first problem I moved the reference to the ice modelling tree on the particle cloud to secondary shape modeling, but even if I did freeze the geometry the export file was empty.

Any ideas?

It worked once!

[Pancho]

P.S.: I just need one frame for a still, not export the whole animation. Strange why freezinging doesn't seem to work.

[Pancho]

The example scene easily saves the instances. I wonder what's wrong in my scene. Sigh!

[guillaume]

The example scene easily saves the instances. I wonder what's wrong in my scene. Sigh!

If you can share your scene (or a similar one) , I'm sure you will get more help from here.

[edschiffer]

great compound, Guillaume, thanks!

just one thing: the Animated parameter is checked on the scene and on the compound, so the instances keep changing.

the compound will be great useful to use Momentum on meshes generated from pointclouds.