Math Nodes

[3dreamstudios]

I have a material that was developed for LW using Math nodes. Basically I use some math nodes to adjust a UV offset for an image giving a texture a random column and row to use inside a UV. I can post the node tree if it would help.

But right now I'm not getting it to convert to Octane nodes, changing out all of the texture etc...nodes for octane versions. Leaving only the math nodes.

Should this work? If not, are there plans to have some simple math type nodes, maybe there are already some I'm missing.

Thanks for guidance!

[juanjgon]

At render time, for shading, you only can use the Octane native nodes. Octane only can evaluate it's own GPU nodes, so any other LW node is not going to work. You have very limited math nodes currently, in the tools nodes (invert, mix, clamp), but not more complex things.

This limitation should be removed in Octane 3 once the OSL is available to write custom nodes and shaders.

-Juanjo

[3dreamstudios]

That's what I figured but thought I'd ask. Attached is the node tree. See anything that could be added to current release...pretty simple math. Multiply, Scaler with min and max, Floor and Divide. Thanks!

[gordonrobb]

If you've got the nodes connected to an octane node, surely it'll work.

[juanjgon]

If you've got the nodes connected to an octane node, surely it'll work.

Nope, sorry, all this nodes are not going to work at all at render time. You can only use Octane nodes.

-Juanjo

[gordonrobb]

Dont get it. I've used non octane nodes before for things like the octane camera focus etc. What's the difference?

[3dreamstudios]

Dont get it. I've used non octane nodes before for things like the octane camera focus etc. What's the difference?

That is true, I did use a scalar node as directed by developer to drive the time of day parameter in the daylight system. hmm....

[juanjgon]

Dont get it. I've used non octane nodes before for things like the octane camera focus etc. What's the difference?

True, you can use some of the LW nodes in the render target because it is evaluated by the plugin while loading the scene, not by Octane at render time. This is the same technique used to rasterize the LW procedurals to use them with Octane.

At render time Octane only can use it's own internal GPU CUDA nodes. The LW CPU nodes can't be used at all. This is why for me, one of the most important feature of Octane 3 is the support of OSL. This can open the door to build custom nodes and shaders for Octane, so if you need a math node, I could build it in OSL for you and add it to the plugin

-Juanjo

[3dreamstudios]

Thanks for the reply. If I understand what your saying certain nodes can be used a "scene load time". But when I use a scalar node to drive the time of the daylight parameter it works fine without having to load the scene each time it renders a frame. It just chews through each frame one after another without "loading" the scene again and again each frame.

Either way that's good news about 3.0 stuff. Each version get's better and better it seems. we've been watching Octane for a while now....just until 2.0 we felt worth jumping in for production!

[gordonrobb]

Sooooo, could he use a normal LW image node, that has the UV changed and input that into the Octane texture node, a bit like the solution that allows for using procedurals in displacement?