LuxCoreRender Forums

Path OpenCL and Sobol

marcatore wrote: Thu Jul 25, 2019 10:37 am I'm not sure...but without them I don't have that fireflies.
I'm preparing a simpler scene and I'll send you.

You are using an extremely small area light with an 90 degree emission angle, it is not a spot light in LuxCore "speaking".

Try to change the light set up from this (i.e. the current one):


to this:


You have also to change the emitting angle to something like 45 degree (from 90). It would be also better to switch to true spot light instead of using area light with emitting angle.

The scene I received looks quite different from the one posted and it is firefly free so I can not directly check this change:

I tried similar setup. Here's 200 samples images.
Bidir+Metropolis: ~
Path+Sobol~
On my cpu Path+Sobol is 3 times faster, but it's just lame. I think Sobol is not needed.

Ok, sorry for the light misunderstanding.

I was quite sure that I used spot light that I haven't checked. Sorry again.

I'll do some tests as you suggested.

About the scene, it's quite strange.
I've just now tested it at home, where I don't have any files or textures related with that scene, and the result of the rendering is this


I don't understand why you have a so dark scene?
Or are you relating to the less furniture present? If yes, I've create a simple scene with the objects with the most visible fireflies effect.

marcatore wrote: Thu Jul 25, 2019 7:21 pm I don't understand why you have a so dark scene?

I need to export the scene in LuxCore format and than render outside Blander, you are probably using some kind of Blender image post-processing pipeline and that kind of stuff is not exported (because it is not done at all by LuxCore). This is the most likely explanation.

By changing the tone mapping by hand I should get the same result. I will check tomorrow.

Area light moved away from the inner part of the light fixture and set a spread angle of 60°



Area light changed to spot light (without moving the lights from the original position)


Actually with spot lights the fireflies gone away so it seems perfect.
Doing this tests I remember that I've already used spot lights but then I've changed to area light cause I dislike the sharp shadow that spot lights do.
In this image there is not the furniture with the shelves near the wall to show you.
The area lights was better to have more smoothed shadows.
Additionally, in this way the inner part of the light fixtures seems OFF... should I use an emission to fake it?



Except for the fireflies, don't you feel that this last image is better than the spot one? Shadows fade smoother, light fixture seems ON and lighting on the wall better spreaded (actually it's the light fixture model that drive the light distribution more or less as in real life)

Dade wrote: Thu Jul 25, 2019 7:34 pm

marcatore wrote: Thu Jul 25, 2019 7:21 pm I don't understand why you have a so dark scene?

I need to export the scene in LuxCore format and than render outside Blander, you are probably using some kind of Blender image post-processing pipeline and that kind of stuff is not exported (because it is not done at all by LuxCore). This is the most likely explanation.

By changing the tone mapping by hand I should get the same result. I will check tomorrow.

These the settings












Camera settings

marcatore wrote: Thu Jul 25, 2019 7:38 pm Doing this tests I remember that I've already used spot lights but then I've changed to area light cause I dislike the sharp shadow that spot lights do.

You could use point lights with some radius > 0 to have smooth shadows, maybe with a spotlight IES profile to shape the cone.

This is a test with point light (positioned in the inner part of the lifht fixture)



Still fireflies.
Could be that positioning light in the inner part of the light fixture, the fireflies will be "emitted" by the light reflected by the light projector?
If yes, I could move away the light but how should I simulate the light fixture illuminated ?

B.Y.O.B. wrote: Thu Jul 25, 2019 7:58 pm You could use point lights with some radius > 0 to have smooth shadows, maybe with a spotlight IES profile to shape the cone.

This, point light with radius (to get smooth shadow borders) and IES spot light profile (to get a cone of light).

Otherwise, have you tried to enable hybrid forward/backward path tracing in your original scene, it should transform that fireflies in nice caustics