LuxCoreRender Forums

Problem 1

Somewhat continuing on the topic of having in-render background visibility without affecting other rays...

Here's my test render that's giving me problems here is some official product render from another company from internet providing cases for those max airpods The point here is having background visible in refractions/specular and not contributing to reflections and diffuse

as you can see here setting up world light to use only specular doesn't make any difference and still it affects lighting and reflections

and here if I enable visibility for diffuse and glossy the only change is visible in the metal parts (all shaders are disney) I'm gonna do this by making 2 renders and compositing background+airpods+clear case as separate parts for now. But it does mean rendering the whole thing 2x. Is there a better workaround or is this a feature reuquest?

Problem 2

Intersecting clear geometry... Is there a way for me to sort volumes maybe to get rid of intersecting artifacts?
It is near impossible to avoid intersections in some cases. For example I also have iphone where backside of phone is glass and then there is a clear case on top of that and these are very tight models for production so in 3D they somewhat intersect at points. I could do some dirty tricks to get rid of it, like removing interior of the case model, but if someone knows a better way, let me know.

here I chose more extreme color to better illustrate that even if I set BG visibility to specular only I still see red bg affecting diffuse and gloss Now that I think of it, If I could turn everything except case into holdout it could help a bit too, which is yet another issue

Maybe Dez could help you ? he the one facing such kind of Product Viz challenge in a daily Workflow

Problem 1.
More composing + less rendering = better result.
We stripped headphones and glasses in different layers of rendering. Install in each layer individual lighting.

What would get transparent glass - do not do world. Use Sun Hemi + HDR.
I use 1, 2 and even 3 Sun Hemi HDR.
I use additionally many small lamps


For each angle, your set of lamps.
Lamps make different forms and textures.
Sometimes I make an array array from a variety of very small.

Problem 2.
It seems to me that it is connected with the settings here:


I note that the increase in Max Epsilon badly affects the preparation of rendering when the GPU is enabled.

Dez! wrote: Mon May 03, 2021 9:27 am I note that the increase in Max Epsilon badly affects the preparation of rendering when the GPU is enabled.

Each different epsilon value requires a re-compilation of the rendering kernels, maybe you mean that? (If the epsilon is no longer changed after that, the kernels will be re-used of course)

I know what kind of compilation of the nuclei.
But I mean that the greater the Max Epsilon value, the longest starts rendering on the GPU.
At values of 1, rendering starts 5 minutes when the same scene starts at 0.1 in 20 seconds.
If you set the values of Max Epsilon 2, 4 ... The start of rendering can not be waited.

For me, this is a big problem, because I use specific settings for scene measurement units:


With these settings, you always have long and tediously select Epsilon values.
Long - because Epsilon artifacts are visible only at maximum resolutions and with an almost final rendering level.

I spend a lot of time and money of the customer to fight the artifacts of Epsilon, and I am very losing in competition with other visualizers.