How can I do a fluid sim in Houdini and render it using VRAY through 3DS Max?

I know next to nothing about Max, so I apologize if this is a stupid question. I looked around online for volume cache I/O for Max for about two hours and really couldn't find anything.

Awesome! Thanks so much, Goldleaf!

1) I heard something about objects getting an automatic glue constraint if they start out intersecting. Do you know if that's true? I suppose that would also be fine. I just don't want things to blow up too much if they're procedurally becoming active, but there are small intersections with the surrounding geometry when it becomes active. Do things normally just explode if they intersect? I'll try it out in the morning, when I'm more awake :-)

2) Thanks! These examples are fantastic! What exactly did you change about the SOP Geometry node that you colored red? All I can see is that Time is set to “Set Always” and SOP Path is set to “Set Initial”. What about that makes animated packed primitives work? Also, I see that weird problem where the geometry disappears when it's cached as well. Ha ha. Weird!

3) I'll check those out. Those look like great resources.

4) I just watched the H13 bullet example again and the last example shows that the force attribute is calculated per piece, and that you can release the constraints based on that attribute. So I can probably get away with just not counting the number of impacts and doing any release based on force (which would probably be better anyway)

6) So the emitter business is using ODE? Not packed primitives and bullet? Is ODE much slower than bullet? I haven't used an ODE solver in about seven years :-)

Thanks again! I really appreciate it!

Thanks! :-)

Does that relationship set up work per body? And does it work with packed primitive rbd objects as well?

Also, I didn't see the deforming geometry check box on the rbd packed object. Is that not available for packed primitives? That would be pretty weird.

Hi – I'm new to Houdini's bullet implementation and I have some questions about it. Thanks very much for any help :-)

1) If objects begin the simulation penetrating each other, is it possible to turn off collisions between those two bodies until they separate? Other implementations of bullet that I've used can do this, but I'm not sure how to turn this on.

2) How do I make an animated collider? It seems like my options are 100% static or dynamic. I want to pull in transform information for my packed primitives and use them as collision objects.

3) How can I get an animated collision object switch over to being an active dynamic body based on something I've set up in SOPs?

4) Can I have an object become active once it reaches a collision threshold, dynamically? I.e. do I get access to the current impact data and correlate that with which packed primitive to set to active? Inside of the sop solver, the impacts data doesn't seem to give me data that I can correlate to actual packed primitive points for me to set their active state.

5) Speaking of the sop solver, the dop_geometry and relationship_geometry don't seem to be pointing to the right stuff by default? I can't see either one, and they have a warning that says that “relnode” is unknown. What's going on here?

6) I was looking at the tutorial for emitting new teapot geometry into the bullet solver. How can I set the collision mesh type (Bullet Geometry Representation) for newly emitted geometry? Is that always set on the RBD packed object/RBD object? Or can I set it later for new geometry I'm adding to the simulation after the start frame?

Thanks again :-)

You might be able to get some cool effects by stretching out a volume, then meshing around it. If you had features inside the cells represented as different fields in the volume, you might see them stretch and split into two as well.

This is terrific. Thanks so much! I'll try it out when I get home in a few days :-)

The plane looks like what I need, but does it provide multiple local planes, if the point cloud search radius is smaller than the entire cloud? Is that what those smaller planes in one of your images are?

Thanks again. I really appreciate it.

Sorry if this has come up before. I searched, but did find a previous thread on the topic.

I'm looking for a VOP or instructions for building a VOP network (or something) to provide the unit vector/slope of a best fit line for a local point cloud.

Basically, a linear regression for a set of local points, on a per point basis.

Is there something like this already? If not, could someone help me build it? My math isn't strong enough to build it myself. I found this: http://en.m.wikipedi…Line_Regression [en.m.wikipedi]

If it was even just boiled down into pseudo code, I could probably build the network, but I just don't know how to translate calculus or linear algebra into simple algebra to turn it into code. Any help would be appreciated :-)

Thanks!