Search found 219 matches

by lighting_freak
Tue Nov 24, 2020 9:39 am
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2978

Re: strange behaviour of homogeneous scattering volume

Hi, thanks for your answers. That is not a property of the scattering volume, but of the surface! On this pictures you may see that the sample plate is almost specular: 20201124_095059.jpg 20201124_094949.jpg Anyway I ran tests with different surface settings (rough, matte translucent, bump) and non...
by lighting_freak
Mon Nov 23, 2020 3:46 pm
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2978

Re: strange behaviour of homogeneous scattering volume

Hello all, I'm still working on the example file... but the topic remains in my mind and also on my desk. I've continued the investigation of the scatter volume and all the tests I've done share also one irregularity. The render results doesn't look blurry. It always appears like there's a colour fa...
by lighting_freak
Fri Nov 13, 2020 9:02 pm
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2978

Re: strange behaviour of homogeneous scattering volume

Hello,
Dade wrote:
Fri Nov 13, 2020 4:39 pm
You can't with FP32, etc.
You mean it's impossible or it will just last long? I'm not looking quick results but for high realism. Is FP32 floating point precision? I don't get the connection between the precision and this surface/volume issue.

Thanks for your explanation.

BR
by lighting_freak
Fri Nov 13, 2020 2:21 pm
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2978

Re: strange behaviour of homogeneous scattering volume

Hi Dade, as you see in the image the reduced path length directly leads to a darkening of the material. This material exists in reality. I have a material sample like this directly in front of me. In my project this diffuse volume will be combined with a rough surface. The real part will be lit by a...
by lighting_freak
Fri Nov 13, 2020 7:30 am
Forum: User Support
Topic: wrong luminance calculation
Replies: 3
Views: 964

Re: wrong luminance calculation

Hello, Let's calculate the factor: 2*pi*(1 - cos(90°/2)) = 1.84030, as well as the ratio of your results: 318310/172966 = 1.84030 :arrow: the same. I don't really understand where this formula is coming from but it seems to cause that trouble. I totally agree. A physics based conversion from Lumen t...
by lighting_freak
Fri Nov 13, 2020 7:20 am
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2978

strange behaviour of homogeneous scattering volume

Hello all, I did a comparision of two almost equal setups. Both are using the same scattering volume definition but one with a perfectly polished surface and the other one with a surface using a little roughness (0,00001). The results look like this: DF23_polished.jpg DF23_little_roughness.jpg Why d...
by lighting_freak
Thu Nov 12, 2020 7:47 am
Forum: User Support
Topic: wrong luminance calculation
Replies: 3
Views: 964

wrong luminance calculation

Hello all, This is the test condition: A light emitting surface with edge length of 1mm x 1mm emits 1 lm of light in an lambertian way. This is observed by a camera very far away (infinte) normal to the light surface. Theory says: luminance = luminous flux / solid angle / projected lit up area lumin...
by lighting_freak
Fri Oct 23, 2020 5:32 am
Forum: User Support
Topic: spectral rendering
Replies: 58
Views: 8401

Re: spectral rendering

Hi, If one coniders scientists and engineers, you have to have a clear idea what features you would offer them (and advertise as such). I really have a clear idea... I'd like to have a photometric real world visualisation, using physics based light sources that interacts with physics based surfaces ...
by lighting_freak
Thu Oct 22, 2020 4:45 am
Forum: User Support
Topic: spectral rendering
Replies: 58
Views: 8401

Re: spectral rendering

Hello, Rolls Royce I don't think that the parameters are to complicated. They in some cases just different. If you really like to remodel real world behaviour you'd probably need even more parameters. The question is where does luxcore want to go to? Does it like to be a cycles clone, or does it lik...
by lighting_freak
Mon Oct 19, 2020 5:27 am
Forum: User Support
Topic: spectral rendering
Replies: 58
Views: 8401

Re: spectral rendering

Hello all, I totally appreciate the discussion about spectral renderings. I agree to all of your pros and cons... my latest thread could point to one more situation that seems to be limited to current RGB solution. https://forums.luxcorerender.org/viewtopic.php?f=4&t=2678 I would like to see a "scie...