first steps on luxcore

[Sharlybg]

Motion blur doesn't work on emitted particles: Alpha5
Blend

particule motion blure.blend

(2.27 MiB) Downloaded 266 times

[Sharlybg]

How it is possible to see the light from the purple cube behind a dark geometry .

blend

particule motion blure 2.blend

(759.26 KiB) Downloaded 265 times

[B.Y.O.B.]

Motion blur doesn't work on emitted particles

It's not implemented yet.

[Sharlybg]

but should we be able to see the purple cube in my scene ?

[B.Y.O.B.]

but should we be able to see the purple cube in my scene ?

No, it should not be visible. Maybe a bug in the depth of field code (could it be that it generates some rays that start below the ground plane?).

[Sharlybg]

It seem that our light sampling isn't good enough. especially for mesh light and HDRi.It is like we produce to much noise no matter the settings. I also see that light with more than 10 triangles are better in cycles than in luxcore .here are my results:

they all run for 60 seconds on GPU without clamping:

Cycles

Luxcore sobol

Luxcore metropolis

Luxcore Bidir

[Dade]

It seem that our light sampling isn't good enough. especially for mesh light and HDRi.It is like we produce to much noise no matter the settings. I also see that light with more than 10 triangles are better in cycles than in luxcore .here are my results:

Are you using a single mesh with more than 24 triangles ?

LuxCore switch direct light sampling off for meshes with more 24 triangles. There is an option to re-enable direct light sampling but I assume it is not exposed in BlendLuxCore.

To check the difference, render an image with exactly 24 triangles and than with 25, you will see an huge difference.

This option is intended for light sources with many hundred/thousand of triangles that affect a very small area of the rendering (for instance a neon signboard, etc.).

In your case, it is the only light source and affect all image so it is very detrimental.

P.S. BiDir ignores this setting because it isn't applicable to bidirectional path tracing.

[Sharlybg]

Are you using a single mesh with more than 24 triangles ?

LuxCore switch direct light sampling off for meshes with more 24 triangles. There is an option to re-enable direct light sampling but I assume it is not exposed in BlendLuxCore.

To check the difference, render an image with exactly 24 triangles and than with 25, you will see an huge difference.

Is there any possibility to enable this automatically inside luxcore so the engine can detect itself when to enable and when to disable ?

[Dade]

Are you using a single mesh with more than 24 triangles ?

LuxCore switch direct light sampling off for meshes with more 24 triangles. There is an option to re-enable direct light sampling but I assume it is not exposed in BlendLuxCore.

To check the difference, render an image with exactly 24 triangles and than with 25, you will see an huge difference.

Is there any possibility to enable this automatically inside luxcore so the engine can detect itself when to enable and when to disable ?

It is exactly how it is working now, using a 24 triangles threshold. The threshold can be raised/lower but you can always build a case where you picked the "wrong" threshold.

Indeed, it is not possible to know how large will be the effect of the light on the rendering without doing the rendering itself.

At the moment there are 3 possible settings:

1) always disabled

2) always enabled

3) disabled if over a threshold, enabled otherwise (the current default)

I can change the default and/or the threshold but you can always build a case where they will not work well.

The real solution is the additional pre-processing phase I was talking about when discussing HDR visibility map (a light cache-like solution).

[Sharlybg]

I can change the default and/or the threshold but you can always build a case where they will not work well.

The real solution is the additional pre-processing phase I was talking about when discussing HDR visibility map (a light cache-like solution).
Top

Aaah Ok understood . will try to avoid some bad cases.

Now i've got time to show some of my observation about HDR sampling efficiency and render preview quality/speed. It is like Cycles Hdri management is faster when Multiple importance is enable.

READ NOTE ON IMAGE FOR BETTER UNDERSTANDING:

Luxcore

Cycles