LightSelect render element only showing direct light, no GI?

[Rob Burns]

I did some searching for this issues and came up short, but perhaps I missed a previous discussion. When I use the LightSelect render element, it only contains the direct component of the lights associated with the element, but no GI or bounced light from them. Perhaps this is totally normal and including the GI would not be possible, but I guess I was expecting the GI component to be there so I could truly adjust lighting in post in a realistic way. Am I missing something? is it possible to have both the direct and bounced light contribution of specific lights separated using LightSelect? If the GI component is not included wouldn't the lighting adjustments I make in post be essentially unrealistic since increasing the brightness of a set of lights would have no effect on the GI in a room?

[Rob Burns]

anyone have any thoughts on this? cheers

[RockinAkin]

The LightSelect render element doesn't include the GI contribution of lights yet unfortunately. It's something I've wished for as well.

As far as I'm aware, the only way to get this from ANY renderer is if it's using bi-directional path tracing.

You can experiment with VRay's bi-directional path tracer by adding it's helper to the 3ds max scene... but it's experimental, slow, and far from production ready.

[jasonhuang1115]

I wish to see this feature for quite a while. Valdo mentioned in several threads that they are working on the BDPT to make this happen. So far of the the renderers I am aware, only Maxwell can achieve this.

[savage309]

VRay RT GPU actually has the GI in the Light Select render element. But it is still not working in the production version.

[jasonhuang1115]

That's good news....hope to see that in VRay for Maya RT and production version soon...
Just curious why the RT GPU has this feature first???

[savage309]

It is easy to implement it for brute force / brute force GI (and since the current GPU version supports only bf/bf, we did that). It is almost undoable for the biased solutions, since the information from which light has this color being produced is lost (and if we keep it, it is going to take a massive amount of memory). We can implement it for bf/bf for the production (and we will have different LS render element for the different GI algorithms; I guess this may happen at some point).

[jasonhuang1115]

It's great to learn a bit ins and outs of the reason behind. Thanks! Not sure if different LS render element for different GI algorithms is the way to go but I look forward to seeing faster BF/BF GI in VRay.

[RockinAkin]

It is easy to implement it for brute force / brute force GI (and since the current GPU version supports only bf/bf, we did that)...

If it is easy to implement for BF/BF in the production renderer - PLEASE do it!!

I would love to have this functionality!

[Dariusz Makowski (Dadal)]

I would like to ask for both maya and max. To have slightly different control over what we get out of it.

Instead of drop down and pick menu lets have checkbox.

1 for beauty
1 diffuse
1 for specular
1 for raw light
1 for GI

And then I can save diffuse+specular+gi in separate files
Thanks, bye.

[savage309]

If it is easy to implement for BF/BF in the production renderer - PLEASE do it!!

I would love to have this functionality!

I may have spoken too early about how easy it is, but after all we have it somewhere in the to-do list.