Better scene converter for opacity to refraction

[Morne]

Hi all

Would be nice if the V-Ray scene converter can take into account the opacity of a standard material and bring that across into the refraction of the V-Ray material.

For quick tests especially on imported scenes with millions of objects and materials, when you run the scene converter you don't know what is suppose to be glass for example

[tashko.zashev]

But why you need this transformation of the mapped opacity into a refractive shader ?
The current conversion is Standard opacity > V-Ray opacity map. Which is the expected result I think.

[Vizioen]

Well I think the problem is that some people use opacity as a way of "simulating" glass. I think Morne received a model from a different software package/user. And they used opacity there to simulate glass. Morne can't you use VMC or Zorb or something for a quick conversion after. And indeed opacity should stay opacity.

[Morne]

But why you need this transformation of the mapped opacity into a refractive shader ?
The current conversion is Standard opacity > V-Ray opacity map. Which is the expected result I think.

I'm not talking about mapped opacity. I'm talking about the opacity feature in the standard shader. Most imported stuff comes in with standard shaders for example from Skethup or Rhino. In max glass shaders has opacity at for example 50. If I can translate that into VRay refraction of 128,128,128 for example it would be great since then at least I can visually see in the viewport what is suppose to be translucent like glass.

For example the typical 3rd party file I get imports as 20K objects with 900 shaders. No time to fix it as half the time I dont have the original software it was created in so got to deal with what I get. Something automated will be much more usefull.
Oh and those 900 shaders doesnt import as "glass", "wood" "masonry" etc. It imports as "material1", "material2" and so on.

[Svetlozar Draganov]

Our material converter doesn't take into account opacity value under the Standard material.
You may use the following converter instead - it does exactly what you like converts opacity value of Standard material to Reflection value in V-Ray material.
http://www.scriptspot.com/3ds-max/sc...converter-v2-5

According to my tests it works on 3DSMax 2016 and V-Ray 3.x although under the requirements it is mentioned up to Max 2014 and V-Ray 2.x

[Morne]

Thanks Svetlozar, I'll give that script a try!
(but I still think the native ChaosGroup one should have an option for this)

[Dave_Wortley]

You can almost logically say if the Opacity Channel has a Map then it should transfer to an Opacity Map if not the opacity colour should transfer to refraction colour. Makes sense to me!

[Svetlozar Draganov]

You can almost logically say if the Opacity Channel has a Map then it should transfer to an Opacity Map if not the opacity colour should transfer to refraction colour. Makes sense to me!

Would you please explain me the logic why the Opacity Color of Standard Mtl should be transferred to Refraction Color of V-Ray Mtl instead of Opacity Color(VrayColor into Opacity slot)?

[Svetlozar Draganov]

Thanks Svetlozar, I'll give that script a try!
(but I still think the native ChaosGroup one should have an option for this)

You are correct I just mentioned that script as a temporary workaround.
I'll make a note into our system once I got a clear explanation why the opacity of Standard Mtl should be transferred to refraction instead of opacity of V-Ray Mtl.

[Morne]

Would you please explain me the logic why the Opacity Color of Standard Mtl should be transferred to Refraction Color of V-Ray Mtl instead of Opacity Color(VrayColor into Opacity slot)?

Because the standard shader doesn't have a REFRACTION value, but a refraction slot for a map. Typically however the opacity spinner is used to simulate refraction for translucent objects for example glass, ice, perspex etc. In the standard shader I think I saw once or twice the refraction slot being used for glass. All other times the opacity spinner was used. This is also typical for programs like Sketchup for example. We use the scene converter not only to make everything VRay, but also to get it more
"correct". Any automation on the road to "correctness" is a great help

[Dave_Wortley]

Would you please explain me the logic why the Opacity Color of Standard Mtl should be transferred to Refraction Color of V-Ray Mtl instead of Opacity Color(VrayColor into Opacity slot)?

If a 'Standard' material has an Opacity colour it's normally trying to be glass, if it has an Opacity map, it's more likely used for cutting out (leafs etc). That would be my basic logic for it!

[Svetlozar Draganov]

Thanks for the confirmation of both of you.
I have added a new feature request about converting Opacity Value into Refraction Color into our system.
Will keep you posted when we have some progress on that matter.

[Dave_Wortley]

It's also worth clarifying that only a bitmaptexture in the map slot would indicate it should be an Opacity Map, if it was a Falloff or something like that I'd expect that to be mapped to the Refraction Map.

[Svetlozar Draganov]

What about if we have a bitmap texture which is supposed to be transferred to Refraction map or procedural one which is supposed to go to Opacity Map?
Wouldn't be better(and more predictable) to transfer all the maps in the opacity slot and only opacity value as a refraction color?

[Morne]

What about if we have a bitmap texture which is supposed to be transferred to Refraction map or procedural one which is supposed to go to Opacity Map?
Wouldn't be better(and more predictable) to transfer all the maps in the opacity slot and only opacity value as a refraction color?

It would be good to have an on off toggle asking the user what to do on each material.

Then it would ask what to do with the color as well as the map. The reason is that often they use clouds as an opacity map on glass but 100 on the opacity spinner. So it looks "more realistic". In this case it would be good to ask the user to ignore the map and just make the refraction 250,250,250 (or ask the user what to make it)