MODO 801 SP4 and the new render cache API

[Steffen Dünner]

Tomorrow is the official release of MODO 901. I guess you guys are prepared and with the flick of a switch we get 901 support in V-Ray, right

P.S.: Great work, Chaosgroup wizards!

[vladimir.nedev]

Tomorrow is the official release of MODO 901. I guess you guys are prepared and with the flick of a switch we get 901 support in V-Ray, right

P.S.: Great work, Chaosgroup wizards!

I am fixing up the export of the new GTR BRDF that MODO has, and will probably add the 901 version of the V-Ray for MODO plug-in to one of the next nightly builds.
There will be more specific work on it, like switching the VFB window to Qt, so it can be docked in the MODO UI, but that will come later.
At least you will be able to use it.

Greetings,
Vladimir Nedev

[swizzelz]

Great news. It's going to be very nice having vray in 901.

Will modos new BDRF be able to translate easier to vray? Meaning, if there is an existing modo material, will rendering it in vray be closer or any more accurate?

I'm sure it's best to always create Vray Materials, but I'm just wondering.

Also, thanks for all the effort on this. I'm finding vrays integration in to modo very smooth and intuitive.

[vladimir.nedev]

Great news. It's going to be very nice having vray in 901.

Will modos new BDRF be able to translate easier to vray? Meaning, if there is an existing modo material, will rendering it in vray be closer or any more accurate?

I'm sure it's best to always create Vray Materials, but I'm just wondering.

Also, thanks for all the effort on this. I'm finding vrays integration in to modo very smooth and intuitive.

Yes, the new BRDF model that MODO uses when "Shading Model" is set to "Physically Based" is pretty much the same
as the V-Ray material's GGX with "GGX tail falloff"=2. The MODO roughness is now easily converted to V-Ray glossiness : roughness = 1 - glossiness.
So if you have a roughness texture, you just need to invert it to use it for the V-Ray glossiness.
Highlights from a simple directional light seem to match perfectly between MODO/V-Ray in my initial tests.

The support for this won't be in the first V-Ray build with 901 support, as I haven't quite finished it.

Greetings,
Vladimir Nedev

[swizzelz]

Interesting, that's what I thought might be the case. I was in the 901 beta and did a render test using 901 and VRay that looked pretty similar. Although, I like using GGX tail falloff as well as Highlight Glossiness. They both offer a nice degree of control and I miss the in modos new native BRDF. I'll probably stick with VRayMaterials.

[vladimir.nedev]

MODO 801 SP5 has just come out, and it fixes the following problems with the render cache API:

1. After the Render Cache API is used, MODO will crash when:
- the current time is changed
- scene is closed
- attempt is made to open an existing scene
- attempt is made to create a new scene

Unfortunately it breaks compatibility with plug-ins built for MODO 801 SP4 that use the render cache API.
Also SP5 introduces a new set of bugs with the render cache API that were not present in SP4.
It no longer returns implicit UVs for "strip" fur materials, so you can't create Feathers in V-Ray (like in the feathery dog example I posted earlier).
When the fur is in "strip" mode, the API will often return invalid triangle indices thus confusing and crashing V-Ray.
When the fur is in "cylinder" mode, not all fur strands are returned.

Because of these bugs, I will disable the Render cache in V-Ray for MODO 801 completely.
You will need MODO 901 to use it.
I might re-enable it, when and if MODO 801 SP6 comes out and if it fixes these problems.

Because the render cache API will no longer be used, V-Ray for MODO will again support MODO SP3, which seems to me more stable than
SP4. It will support SP4 and SP5 as well.

I will write back here, when I've switched off the render cache API in the nightly builds.

Greetings,
Vladimir Nedev

[vladimir.nedev]

For tomorrow's nightly builds (the ones from 2015-06-28 ) I've switched back to using the first MODO 801 SDK (before any service pack).
The V-Ray for MODO plug-in will again load in all versions of MODO 801 (not just SP4 and SP5).
The Render Cache API is now used only in MODO 901, as it is too buggy in MODO 801 SP4 and SP5.
Also I have found some strange bugs in "modo_cl.exe" in MODO 801 SP4 and SP5 , which prevent me from using them to run the V-Ray for MODO tests.
For a bug that I think is SP4/SP5 specific, see here " http://forums.chaosgroup.com/showthr...s-disappearing

Greetings,
Vladimir Nedev