OctaneRender for Modo (Windows) 1.52 [STABLE]

[face_off]

This is working great, but I would prefer the files were saved into AppData\Roaming\Luxology\. I think it might be cool to expand on this so we can save/load presets too.

Savng to AppData\Roaming\Luxology\ is implemented in the next release.

Paul

[funk]

If I select an area light and press "create octane emitter" I get this popup during the node creation:

octane.materialMacro
Command disabled

The nodes seem to be set up correctly though

[funk]

Another enhancement you could make during area light conversion would be to create an ellipse mesh if area light shape is set to ellipse.

For now I just subd the geometry you create and scale it up a little

[funk]

Paul, I just want to say that it's really great finally having octane in modo. I want to thank you for doing such an awesome job.

You've fixed bugs really quickly (even working around modo's own bugs) and you've also added a lot of my feature requests.

I actually havent had any crashes yet with the latest release. We need more people testing it though. I'm starting to feel like I'm the only one posting here lol.

[funk]

I'm having an issue with a complicated node setup. I have a greyscale color plugged into the roughness of a specular node with a value of 0. This seems to work fine (my material has no roughness), but after I reload the viewport or scene, the material is rendered with roughness greater than 0.

It seems the greyscale color node is not passing the value or something...

I'm attaching a stripped down version of the scene with only part of the node setup:
1. Open the viewport. You will see a head rendered with blurry reflections (this is incorrect)
2. Click the oldmanhead override then set the octane greyscale color to 0 (even though it's already 0). This forces a refresh and you will notice the material will change to no roughness.
3. Press the reload scene button. It goes back to being rough...

[face_off]

I think you got the formula slightly wrong. If I make an adjustment it works:

IOR = (1 + sqr(spec)) / (1 - sqr(spec))

So for 4% specular we should get 1.5 IOR

1.5 = (1 + sqr(.04)) / (1 - sqr(.04))

Could it be that Conserve Energy ON = Octane index 8, and Converse Energy OFF = Octane index 1.3?

With Converse Energy ON, it seems a simple equation of Octane Specular = Modo Reflection amount/color, and index = 8.

Paul

[face_off]

Another enhancement you could make during area light conversion would be to create an ellipse mesh if area light shape is set to ellipse.

I think it's trivial to implement this, however a multi polygon emitter is a lot less efficient than a single poly emitter. But the point light is a sphere, so it's probably not a big issue.

Paul

[funk]

I think you got the formula slightly wrong. If I make an adjustment it works:

IOR = (1 + sqr(spec)) / (1 - sqr(spec))

So for 4% specular we should get 1.5 IOR

1.5 = (1 + sqr(.04)) / (1 - sqr(.04))

Could it be that Conserve Energy ON = Octane index 8, and Converse Energy OFF = Octane index 1.3?

With Converse Energy ON, it seems a simple equation of Octane Specular = Modo Reflection amount/color, and index = 8.

Paul

But that would limit us to only 2 IOR (index) choices of 1.3 and 8. We need to be able to control the index (IOR) freely and the only value that directly relates to it is modo's specular amount.

I think the whole point of auto "on the fly" conversion is to get as close to the modo render as possible, so we can load an old modo scene and have a reasonable octane render with minimal tweaking. Otherwise there is no point even trying to get close if we have to override everything anyway.

I dont think we should be using the "conserve energy" to control an IOR "switch" in octane because that's not what its being used for in modo.

In octane there are 2 ways to control reflections
1. Set glossy index (IOR) to 1 (this turns IOR/fresnel OFF) and control the reflection amount via glossy spec. This isnt actually physically correct because there is no fresnel, but its useful for mirrors and chrome etc that need to be shinier than IOR of 8 (the max value octane allows)
2. Set glossy index (IOR) to greater than 1 and glossy spec amount to 1. This gives physically correct reflections with fresnel

I think we can probably replicate those 2 options in a way that will make more sense and also works with (and visually matches) our older modo scenes:
1. If modo fresnel is 0%, set glossy index to 1 and glossy spec to (modo spec amount * modo spec color)
2. If modo fresnel is > 0%, then calculate the glossy index (IOR) from the modo spec amount using IOR = (1 + sqr(spec)) / (1 - sqr(spec)) and glossy spec to modo spec color.

I'm already doing this manually and get extremely close renders when comparing the modo and octane output.

If you want octane to match modo as closely as possible, use these settings for the camera imager:
exposure = 1
fstop = 1
ISO = 55
GAMMA = 2.2
Response = LINEAR/OFF
Vignetting = 0

Dont use physical skies, but flat color (texture environment) or HDRI


This gives you a gamma corrected render with no camera response and an exposure white point very close to modo's default.
Then when you do material changes you can see how closely they match between the 2 renderers

[face_off]

If I select an area light and press "create octane emitter" I get this popup during the node creation:

octane.materialMacro
Command disabled

The nodes seem to be set up correctly though

This is an excellent example of adding an enhancement which breaks something totally unrelated. Which is why I can be resistant to some changes In this specific case, the change to convert Modo materials with no specular to Octane diffuse rather than glossy means than when the "Convert to Emitter" process tries to add an emission node, the command to convert the material from a glossy to diffuse node fails (and pops the error).

Paul

[face_off]

I'm having an issue with a complicated node setup. I have a greyscale color plugged into the roughness of a specular node with a value of 0. This seems to work fine (my material has no roughness), but after I reload the viewport or scene, the material is rendered with roughness greater than 0.

It seems the greyscale color node is not passing the value or something...

Good pickup - fixed in the next version.

Paul