octane 3 volume render for smoke/fire

[atmos89]

will we be able to render fume fx or phoenix fd in 3ds max with octane plug ?

[Bulwerk]

I think it all depends on the plugins (FumeFX, Phoenix FD) ability to write in OpenVDB. And since both can I think the answer is yes.

[atmos89]

that would be great

[linvanchene]

Can developers already share some information how exactly OpenVDB is going to be integrated with OR?

Will users be able to CREATE volumetric effects from scratch in OR or just to RENDER volumetric effects created with 3rd party applications?

- - -

I tried to have a look at the official OpenVDB website to get some clues how that might work:

http://www.openvdb.org/

I also read trough the v3 dev update

viewtopic.php?f=9&t=50956

Volume rendering

As you already have seen in the v3 preview, we added volume rendering of OpenVDB files. Of course, plugins or Lua scripts can also feed volumetric data directly into Octane without going through files. Since the preview, various improvements got implemented, including the support of hierarchical grids.

There is still lots of work to be done, especially on the way how you define the medium appearance, but it's already quite useful for many cases.

The way this was phrased I start to get the impression that I may have wrong hopes about the volumetric features for OR 3. Maybe it would also help other users if those questions could be addressed now in order to prevent potential disappointment when OR 3 is released.

- - -

1) Will it be possible in ALL OctaneRender plugins to procedurally create smoke and fire effects WITHOUT the need for 3rd party OpenVDB plugins?

Example:
The user places any kind of 3d object in the scene in any OR plugin.
The user connects a "volumetric" node to the 3d object
The users moves some sliders to change how the smoke or fire effect looks like.

Side Note:
The underlying assumption was that a core feature of any advanced render engine should be to create procedural materials.

Procedural displacement lets the users create custom shapes at the surface and edges of a 3d object.
Procedural volumetrics lets the users create custom shapes inside of a volume.

Fractals or other complex mathematical functions are used to create the shapes.
In the User interface sliders with real world relevance are provided for the casual user so they can configure the shapes without knowledge of the underlying formulas.

examples: cloud/smoke thickness, selection of cloud types cumulus, stratus etc.

Advanced users may be able to directly control the shapes by combining fractal nodes.

alternatively:

2) Will Otoy or a third party create an advanced OpenVDB plugin for OctaneRender standalone?

Example:
The user creates a scene in their host software and exports it to OR standalone as ORBX.
The user then can use an advanced OpenVDB plugin in OR standalone to add the smoke / fire effects

or

3) Will only a small selection of OR plugins for host software with 3rd party OpenVDB plugins be able to render smoke and fire effects?

- - -

[haze]

These are all great questions.

OctaneRender will not procedurally generate smoke and fire. Generating realistic smoke and fire datasets is a very complicated process and involves running very computationally expensive simulations. Equally as complicated is the process of image-order rendering of these datasets.

The purpose of OpenVDB is mostly to have an efficient way to store volumetric data in memory and on disk. It has evolved into a more general toolkit that also lets you accomplish other things, such as fracturing volumes, converting meshes to volumes and vice versa. However, it does not include a computational fluid dynamics solver, and therefore it cannot procedurally generate smoke or fire.

Will it be possible in ALL OctaneRender plugins to procedurally create smoke and fire effects WITHOUT the need for 3rd party OpenVDB plugins?

OpenVDB is fully integrated as a library in Octane. We therefore have access to all of the OpenVDB SDK. Say for instance you're working in Houdini with the Octane plugin. You'd procedurally generate a volume in Houdini, and the OctaneRender plugin would render it.

If you were running Octane standalone, then you would need to generate the volume in a package like Houdini, and export it to a VDB for Octane to load. Or you could generate the volume in TurbulenceFD and export it to a VDB which Octane would load. We rely on computational fluid dynamics (CFD) solvers such as TurbulenceFD to generate realistic volumetric effects, which they are very good at doing. It takes a considerable amount of computing power to do this (therefore sometimes takes a long time), and they often use GPUs to speed up their simulations.

2) Will Otoy or a third party create an advanced OpenVDB plugin for OctaneRender standalone?

At the moment we do not have an SDK that will let you write plugins for OctaneRender standalone. We rely on third party packages such as TurbulenceFD for generating smoke and fire effects. In other words, you would typically either:

If your software supports procedural volumes directly:
1. Create a scene in your host software,
2. Create a volume in your software, then export for Octane
4. Load your scene in Octane standalone
4. Render in Octane Standalone

Otherwise
1. Create a scene in your host software,
2. Otherwise, generate a volume in TurbulenceFD for instance, and export to VDB
4. Load your scene in Octane standalone
5. Load your volume
4. Render in Octane Standalone

Will only a small selection of OR plugins for host software with 3rd party OpenVDB plugins be able to render smoke and fire effects?

If you have host software that does not support OpenVDB, plugins are still able to render these. If you have host software that does not support volumes at all, then you will need to export for Octane standalone, and generate volumes in a third party CFD solver like TurbulenceFD.

We intend to make the most of the OpenVDB SDK in due course. Currently, the bulk of the work for volumetric rendering was to upgrade the render engine.

[profbetis]

Will Octane be able to have procedural volumetrics via the pre-existing 3D/4D noise generators (with no simulation), or would this still have to be done in third-party software?

[haze]

It is possible to write a Lua script for Octane that generates a random volume (using eg Perlin noise) -- of course, depending on what kind of volume you need, the script would need tailoring. If there is enough interest, I'll write this script after the first release of Octane 3. Be aware, without a simulation and just random noise, it is very difficult to generate something that looks good. It strongly depends on what you are trying to accomplish.

[profbetis]

I've used the turbulence generator go make some fairly nice looking clouds. If this was able to be done without a workaround (viewtopic.php?f=9&t=44337&hilit=procedural+clouds) that would be awesome and probably a lot faster.

[coilbook]

how do we get volumes into 3ds max to create fire and smoke? Lets say I need to create an animation of fire coming out of the window?