OTOY Forums

Hello,

I have a particle simulation that needs 10 different instances randomly applied to the particles.

How do you apply multiple geo and materials to instances?

thank you

R

Hi,

You can use the "instance" point attribute to set the master object to be used at each point. You have more details in the docs:
https://docs.otoy.com/Houdini_Plugin_Ma ... s%7C_____6

Thanks,
-Juanjo

Yes but how do I randomize materials on these instanced points?

thanks

I'm afraid that currently this is not possible in Octane. The instances materials can't be overridden. You are going to need to have several copies of the same object, each one with one material, and instance them randomly.

At shading level, you have the Random Color VOP, that computes a random value for each instance. Perhaps with this node, you could build a shader with several materials mixed using the material mixer node. This node can also be used with the gradient node and others to render shader variations on each instance.

Hope this helps,
-Juanjo

juanjgon wrote:Hi,

You can use the "instance" point attribute to set the master object to be used at each point. You have more details in the docs:
https://docs.otoy.com/Houdini_Plugin_Ma ... s%7C_____6

Thanks,
-Juanjo

Maybe little oftopic question: can I export instanced geometry (on particles, stamped... whatever) in ORBX and render them in standalone? Of course, with animation, not only single frame.
If yes, is it exported as baked geometry or like Octane instances/scatter?

Yes, you can export the animated scene to an .orbx file. You only need to enable the export options in the ROP node and render the scene. The instances will be exported as Octane instances, storing in the .orbx file only the master object and the Octane scatter information.

Thanks,
-Juanjo

juanjgon wrote:Yes, you can export the animated scene to an .orbx file. You only need to enable the export options in the ROP node and render the scene. The instances will be exported as Octane instances, storing in the .orbx file only the master object and the Octane scatter information.

Thanks,
-Juanjo

Thank you Juanjo,
I managed somehow to export it in orbx and to get scatter nodes in standalone, but other problem occurred, and the problem is that scatter is exported in only one frame, it is static. Everything else has animation, but scatter no. Instances are not moving. Am I doing something wrong or I understand you wrong about scatter animation? I need to preserve point animation over what I do scattering.

Yes, I see. Probably this is a limitation in the scene export functions perhaps related to the fact that the number of particles can be not the same in all the frames, so the object animation at point level is not possible. In this case, the only solution is to export a .orbx file for each frame, but I'm not sure if this is something useful in your workflow.

Thanks,
-Juanjo

juanjgon wrote:Yes, I see. Probably this is a limitation in the scene export functions perhaps related to the fact that the number of particles can be not the same in all the frames, so the object animation at point level is not possible. In this case, the only solution is to export a .orbx file for each frame, but I'm not sure if this is something useful in your workflow.

Thanks,
-Juanjo

Damn, but is it possible somehow to export/render sequence of csv files (as we have only csv)?

Hmm, I don't think so. Perhaps writing a script in Houdini to export this kind of files from Houdini could be possible, but not directly from the plugin.

Sorry for the question, but why do you need to export the scenes to Standalone, to render them in a farm or in the cloud? ... I'm afraid that in scenes with changes in the objects topology, export a sequence of .orbx files is the only solution currently.

Thanks,
-Juanjo