Volume Item rendering Tweet

[portnicki]

Hi,

I know this has been already talked about here, and yes - I've seen the video tutorial for this, but it still doesnt work for me.

How do you render the modos native Volume Item?
I've created a simple Sphere (to be used as the source for the VDB Voxel), a Volume Item and also a VDB Voxel Item.

I've hooked up the VDBVoxel Node to the Volume node in the Schematic. And I've set my Sphere as the Source Item for the VDBVoxel.
According to the video this should be enoght for the plugin to translate this to Octane.

So here's what it looks like in modo vs. Octane

I'm also attaching the scene file should this help.

[face_off]

This functionality seems to be working differently on different version of Modo, as Foundry have been making internal changes to the way VDBVoxel info is processed. Which version of Modo are you using pls?

Paul

[portnicki]

Hey Paul. I'm on 902 SP3

[face_off]

On the scene you sent me - disable the visibility on the Sphere item. Then add a Group to the Shader Tree and set the Item to Volume, and add a new Material. This material converts to the Octane material. You can then add an Octane Override to that Group, and in the override, add a NodeGraph node and connect it to the Volume Item node input. Open the NodeGraph node and setup your Volume material. Doesn't look anywhere near as good as a VDB, but roughly works.

Paul

[portnicki]

On the scene you sent me - disable the visibility on the Sphere item. Then add a Group to the Shader Tree and set the Item to Volume, and add a new Material. This material converts to the Octane material. You can then add an Octane Override to that Group, and in the override, add a NodeGraph node and connect it to the Volume Item node input. Open the NodeGraph node and setup your Volume material. Doesn't look anywhere near as good as a VDB, but roughly works.

Paul

Hey Paul. Thanks for taking the time to investigate. Unfortunatelly for me it's still a no go.
I just get the spehere rendering, no Volumes at all.

I've got to admit that I wasnt working with the latest Octane version (I was on 3.04) but as soon as I noticed - I've upgraded to 3.06, but it's still not that.

Can you send me my scene back after you modified it?

Another problem that I'm having is that after I create a Node Graph - when I click Edit Node nothing happens. No windows pop-up in order to modify the node. I've even tried opening Octane standalone on it's own along modo but that doesnt do anything at all either.

[face_off]

The sphere is still visible in the Modo Item list. May I suggest following my instructions again?

The Edit Node will only work if the Viewport is open.

Paul

[portnicki]

The sphere is still visible in the Modo Item list. May I suggest following my instructions again?

The Edit Node will only work if the Viewport is open.

Paul

Paul I've followed your instructions as close as I possibly can.
The screenshot you mentioned that my sphere visibility is turned on - yes, because I'm trying everything that comes to mind because it doesn't work for me when I follow your workflow. I, of course, tried this as well with the Sphere visibility turned OFF.

check the screenshot please.

I've also tried turning on and off the 'Live Geometry Update', I've tried turning on/off the "Use modo render cache" in the settings.

The only thing that kinda worsk is 'Generate Voxel Mesh' in the VDBVoxel settings. but I just get this weird geometry, nothing 'smokey' visually.

[face_off]

If I load the scene you sent me into Modo 902 SP3, then turn the visibility of the Sphere item OFF, then open the Octane Viewport (with plugin version 3.7.0.125), I get the following, which is definitely showing a voxel item rendering in Octane.

Regarding the Edit Node button - it will do nothing if that Octane Override material is not connected to a Mesh item in the Octane nodegraph.

Paul

[portnicki]

If I load the scene you sent me into Modo 902 SP3, then turn the visibility of the Sphere item OFF, then open the Octane Viewport (with plugin version 3.7.0.125), I get the following, which is definitely showing a voxel item rendering in Octane.

Regarding the Edit Node button - it will do nothing if that Octane Override material is not connected to a Mesh item in the Octane nodegraph.

Paul

Ok, with the latest TEST version indeed it does work now. I was on the Stable version of the plug-in.

Nevertheless, I'm still doing my project with Volumes on the CPU as I experience an instant modo crash the moment I try to use a Surface Particle Generator as the Source Item for VDBVoxel.
Any chance you could try to replicate this on your system as well, Paul?
Create a Surface Particle Generator (with a Source Surface: "Sphere" in case of my file) and then try to use that Generator as the Source Item for the VDBVoxel.

Not sure if it's a plug-in's bug or modo's but I suspect it's the first one, as modo's renderer renders this setup.

[face_off]

Nevertheless, I'm still doing my project with Volumes on the CPU as I experience an instant modo crash the moment I try to use a Surface Particle Generator as the Source Item for VDBVoxel.
Any chance you could try to replicate this on your system as well, Paul?
Create a Surface Particle Generator (with a Source Surface: "Sphere" in case of my file) and then try to use that Generator as the Source Item for the VDBVoxel.

I have been able to replicate this crash. The problem is that Modo is not providing a bounding box for the volume, so there is no way to convert this scenario into Voxels for Octane to use. The crash is fixed in the next release of the plugin (but no volume will render in this case).

Paul