Light passes

[lacilaci]

So ive been asking long time for lighting exclusivity like corona or vray does (using lists of objects linked to linghts)

It seems another way of doing this (from user/blender berspective) is similar to octane's light pass system where emitters have their id 1-8(not sure why 8 maybe hw limitation but might be very well enough)

Then every object has a property with all the passes enabled.

So by selecting light id from emitter and selecting/deselecting appropriate ids on object you can get exclusive/inclusive lighting for object without compositing in post.

So i don't know how exactly it works behind the scenes but maybe we could get system like this in luxcore?

[lacilaci]

here's an example of this feature, a still frame from anim. I'm doing in octane.

Now all this is doable in luxcore

But. To achieve cloud like look of lighting I had to use 4 lights that are just affecting the VDB object itself.
This in-camera compositing is a huge timesaver cause we can in interactive viewport shape out object and product lighting so that they "pop" and don't appear flat...

[lacilaci]

I mean, we can do nice in luxcore too

but without dedicated lighting it's way more work and I personally wouldn't bother...

PS: this isn't speed comparison, octane was 30 seconds and it shows some ugly noise but it's for a small quick anim. I left luxcore render ~10 minutes.

[Sharlybg]

How fast it is when you use emission setting in volume node ?

[lacilaci]

How fast it is when you use emission setting in volume node ?

I don't know how would that work...
But anyways, I'm not comparing speed, just saying that having exclusive lighting is a very nice feature to have...

But, in general after few days of testing I'd say octane is about 3x faster on average, although I think a lot of that comes from
1.clamping that is very usable with very low values,
2.portals - no preprocess, no artifacts, no troubleshooting in case of low clamping,
3.AI lights - I don't know if that feature has to do anything with AI, but in some cases I've seen some serious boosts - even lighting openVDB volume was sped up a LOT with this feature turned on... probably a system to handle how to sample multiple lights efficiently (does slightly change lighting though, but is stable cross frame and with moving objects!)
4.cuda maybe (if we assume nvidia sucks on opencl) - note that I'm currently not subscribed to otoy so this is cuda not rtx which I think could easily be 2x faster...

But I'm not going to do head to head comparison, not anytime soon at least. It is interesting to see how far luxcore has come, but at the same time how much there is still to improve..

[Sharlybg]

I can understand the point of having this nice features. It is like hybrid glass it can save a lot of time and add flexibility to the workflow.

The problem is the lack of Devs. Dade is currently on this cuda/opencl / rtx great heavy feature. BYOB / Neo / u3dreal / Alpistinho and other are more on the addon side

I wonder if there is a way to attract more Devs.

Or this google summer of code. I don't know how it work.
Personally i would like to see online learning sampling in lux
We need help. Crowfunding ?

[B.Y.O.B.]

It is good to have these discussions, but please stay on topic and open new threads for posts that stray away from the original topic.

[Sharlybg]

It is good to have these discussions, but please stay on topic and open new threads for posts that stray away from the original topic.

Sure sorry