OctaneRender for Modo (Windows) 1.52 [STABLE]

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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 am getting values like 138 for the index using this formula which doesn't sound right - so these will cap to 8. Plus - as "index" goes up, IMO diffuse should go down - so if you have a white Modo diffuse, things look odd. Buts it's definitely progress - so I will post the update for you to try. If Modo diffuse = 0, the conversion is very close.

Paul

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I have posted a new build, and if there are no major issues found, I will update the TEST version at the top of this thread.

1.50.0.51
- Default kernel, camera and environment settings are now stored in AppData\Roaming\Luxology\, and are now loaded at Modo startup, so you will need to restart Modo after saving defaults in order for them to take effect.
- Fixed crash when performing a Bake operation in ACS.
- Fixd warning given from the Create Octane Emitter function
- The Create Octane Emitter function now supports eliptical light shapes (creating an eliptical emitter)
- Fixed issue where the Greyscale Color nodes where not correctly setting the value when the scene was loaded into Octane
- Change the glossy "index" conversion to (1 + sqr(Modo Specular or Reflection)) / (1 - sqr(Modo Specular or Reflection))

http://render.otoy.com/customerdownload ... _64bit.exe

Paul

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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 am getting values like 138 for the index using this formula which doesn't sound right - so these will cap to 8. Plus - as "index" goes up, IMO diffuse should go down - so if you have a white Modo diffuse, things look odd. Buts it's definitely progress - so I will post the update for you to try. If Modo diffuse = 0, the conversion is very close.

Paul

What value are you using to get 138? (Edit ahh yes you will get high IORs for high spec values obviously)

If you have a white modo diffuse and enable "conserve energy", modo automatically lowers the diffuse amount as you raise the spec amount.

An IOR of 8 is about 60% specular (this would give you 40% diffuse)

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If you have a white modo diffuse and enable "conserve energy", modo automatically lowers the diffuse amount as you raise the spec amount.

Ah, that makes sense. Something to keep in mind when testing - the Octane plugin does "specular" as a Grayscale Color, not RGB Color. The next version I will cap the index to 8.

Paul

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OK I did a quick test with the new version, but you are still setting glossy specular = modo specular amount. This gives the wrong result. Glossy specular needs to be 1

I'll try and post some pics and a scene to clarify things

UPDATE: The attached image shows you which values the override should be using to match modo. I have also attached the scene

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OK I attached an image and a scene to make myself clearer.

Right now the "on the fly" conversion is not setting specular to 1.

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If you have a white modo diffuse and enable "conserve energy", modo automatically lowers the diffuse amount as you raise the spec amount.

Ah, that makes sense. Something to keep in mind when testing - the Octane plugin does "specular" as a Grayscale Color, not RGB Color. The next version I will cap the index to 8.

Paul

Yes but you can plug an rgb into the spec (eg to do colored metals like gold you plug a gold rgb into spec and set diffuse to 0). Am I missing your point?

And yes you will need to cap the index to 8 since octane caps to 8 on standalone

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If anyone is interested in using IOR values in modo, I have a little script here:
http://community.thefoundry.co.uk/discu ... 559#776559

It pops up a little window that lets you enter an IOR and converts it to the correct modo spec value. It also enables some other stuff to make it physically accurate.

You can use this to compare your modo and octane materials easier

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OK I did a quick test with the new version, but you are still setting glossy specular = modo specular amount. This gives the wrong result. Glossy specular needs to be 1

I'll try and post some pics and a scene to clarify things

UPDATE: The attached image shows you which values the override should be using to match modo. I have also attached the scene

That helps. You can redownload and install 1.50.0.51 to see the change. The main issue now is if the Modo material is highly reflective, and also has a high diffuse value - but all other combo's seem to work well.

Yes but you can plug an rgb into the spec (eg to do colored metals like gold you plug a gold rgb into spec and set diffuse to 0). Am I missing your point?

If the Modo material has a colored specular color (a rare situation), it will still convert to a grayscale Octane texture. But yes, you can override the material and set whatever color you want.

Just on the Conserve Energy reducing diffuse - the plugin does not see that - it get diffuse amount/color from Modo pre any Conserve Energy adjustment. Perhap clicking Conserve Energy multiplies the diffuse by the inverse of the reflection?

Paul

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Wow Paul I didnt expect you to make the changes right now.

I know's its been a looong day. Great job and get some rest


I have some thoughts about highly reflective materials too, but I'll leave that for some other time