Indigo Renderer Forum

I'm testing Indigo with interior scene Classroom.
I would to render with GPU using portals on windows.
But I have a litle problem because sun disapear in the room.
It's working when I'm computing with CPU...
Is there imcompatibility btwn GPU and portals?

Scene without portals. Sun appears. Scene with portals. No sun and fireflies

Hi,
The problem is that GPU forces render mode to single-directional path tracing, which doesn't work well with exit portals. Exit portals only work well with bidirectional path tracing.

Thanks for your answer.

So do you have an advice to improve interior render in interior scenes?
if the solution is not in software, is it possible to render on network with GPU on each slave?

And to finish, do you plan to add multi GPU and/or improve pathtracing in GPU mode?

Hi Gzavye,

So do you have an advice to improve interior render in interior scenes?

Probably the most robust method, as it always is, would be bidir with MLT. Exit portals can be used with MLT also, as Ono said the "sun not showing through portal" issue is intrinsic to single path tracing based methods (rays are shot from the camera only and odds to hit the tiny sun are therefore pretty sparse among all possible bouncing combos).

My workflow for evaluation would be:

1: remove EPs and test GPU.
2: add EPs and test bidirectional PT
3: add MLT on top

Most often I would use bidir+MLT but that's just me, I even used that mode for the wheat field renders (exteriors, see this post and above. hmm now I see it's undersampled after 15mn).

if the solution is not in software, is it possible to render on network with GPU on each slave?

I don't own a network (have single node) but anyways network rendering will not make PT behave better with sun and EPs. Yes, slaves will use GPU if the hardware requirements are met.

And to finish, do you plan to add multi GPU and/or improve pathtracing in GPU mode?

Multi GPU is certainly planned because lycium, who worked a lot on the current PT implementation, mentioned that it would happen at some point.

Despite its limitation with sun trough EP (wether it can be adressed I don't know) Indigo's PT is far from brute force, "smart" rather. It's logical enhancement is bidir (PT, but also shot from light sources with importance sampling).

cheers

gzavye wrote:Thanks for your answer.

So do you have an advice to improve interior render in interior scenes?
if the solution is not in software, is it possible to render on network with GPU on each slave?

And to finish, do you plan to add multi GPU and/or improve pathtracing in GPU mode?

Hi gzavye,
We do indeed plan to both add multi-GPU support, and to support bidirectional path tracing with GPU acceleration.

Hi gzavye,
We do indeed plan to both add multi-GPU support, and to support bidirectional path tracing with GPU acceleration.

Is this this implemented meanwhile ?

Kind regards
Alain

OnoSendai wrote: ↑

Wed Apr 18, 2012 10:12 am

We do indeed plan to both add multi-GPU support, and to support bidirectional path tracing with GPU acceleration.

It's now eight years since this statement, as many people like me are using Indigo do interiors, I wonder if we will ever do bidirectional path tracing + GPU in Indigo.

Is there any hope of that, or has this hypothesis been abandoned?

Thank you
AD

Hmm maybe, but some kind of exit portal improvements for single-dir might be a better approach for GPU initially.

Thank you for your answer, Indigo is an excellent product that I have been following for years because of its physical precision of materials.

However, the speed of calculation is also important for those who cannot afford over a thousand Euro video cards to be used with a "brute force" approach.

Some clever optimization in the direction of exit portals is wellcome !

AD