Indigo Renderer Forum

Hi there,

I just rendered my glass scene again over night (17h) with a little dispersion.
However the Result is not giving me what I have expected.

Render algorithm was MLT-BiDir but it looks the same in Pathtracing-BiDir.

The Renderer was Indigo fo Cinema 4D 3.8.26.2
Cauchy B Coeff was 0.005

Here is the original render. Same Material but without the Cauchy B Coeff
It looks more natural (is not brighter then the background).
Also notice the silhouette of the glass thickens inside the glass is much more pronounced with the Cauchy B material.
Cheers,
Raphael

This is strange and definately shouldn't look that way. Did you check your scene scale?


Cheers, zeiti

Hi

The scene was lit by an environment map?

zeitmeister wrote:This is strange and definately shouldn't look that way. Did you check your scene scale?
Cheers, zeiti

The Scene scale should match real world. I´m not sure if it fits exactly because I do not know exactly what scale is exported by cindigo. But at least in C4D everything is in scale.

zeitmeister wrote:This is strange and definately shouldn't look that way. Did you check your scene scale?
Cheers, zeiti

Yes the scene is lit entirely by a HDRI 360° map.
I should mention that this is the result of a linear output. (Untonemapped EXR)

It looks perfect with Cauchy B set to 0.

Cheers,
Raphael

Dear Raphael,

Cindigo will export in scale which is chosen in Render Setting, Enviroment, Scene scale. I think it just takes the numbers from the scene and it just takes them as they are, without conversion. But I am not sure about that. To avoid all the confusion about the scale etc. I make sure my project settings say the same scene scale as Scene scale in cindigo's render setting, which is the same as unit display in C4D's preferences. Play safe!

Would love to hear how this develops. Never had any problem with CBC before.

What Happens if you use the cindigo version before? And does it come correctly of you use a coefficient of 0.001?


Cheers, zeiti

Oh my. Though Indigo at least had its basics right.

Hi, send over the scene, I'll take a look (eventually).

thesquirell wrote:Dear Raphael,

Cindigo will export in scale which is chosen in Render Setting, Enviroment, Scene scale. I think it just takes the numbers from the scene and it just takes them as they are, without conversion. But I am not sure about that. To avoid all the confusion about the scale etc. I make sure my project settings say the same scene scale as Scene scale in cindigo's render setting, which is the same as unit display in C4D's preferences. Play safe!
Would love to hear how this develops. Never had any problem with CBC before.

Yes that´s what I have been doing too. I checked the scene scale with the apperture. Whrong translations end up with the wrong DOF. So if the DOF is way to strong or not there with a Apperture 3.5 you know there is something off the scale.

I have set the Scale to mm within C4D and within the Exporter.
I changed it to cm and to m just to see if it makes a difference. But unfortunately it does not. Cauchy B always has that magenta tint.

zeitmeister wrote:What Happens if you use the cindigo version before? And does it come correctly of you use a coefficient of 0.001?
Cheers, zeiti

No I have not checked yet. Maybe I should.
I have instead exported it to the latest Indigo standalone v3.8.29

I added some pictures:
I will upload the scene later.

Cheers,
Raphael

As Promised here´s the scene.
I hope this *.pigs file works!

If not just write me a line!

GLASS-SCENE

Cheers,
Raphael

Thank Sliverwing.
Looks like it's a problem with the combination of dispersion (single wavelength rendering), and non-post-process aperture diffraction.
Easy workaround - use post-process aperture diffraction only (or turn it off).

OnoSendai wrote:Thank Sliverwing.
Looks like it's a problem with the combination of dispersion (single wavelength rendering), and non-post-process aperture diffraction.
Easy workaround - use post-process aperture diffraction only (or turn it off).

Oh such an easy fix. Thanks a lot for having a look at the scene!
Much appreciated!

Cheers,
Raphael

Sorry for being so picky.
Yes the Aperture Fix got rid of the coloring. But I still get this stange "Artifact" in the rendering with Chauchy B Coeff. The Silhouette of the glass gets much more pronounced (Marked Green). I think there is something off!

P.s. I used the old colored rendering for comparison. The test with the Aperture fix only gets rid of the color!
Cheers,
Raphael

That's no problem for being picky, good spotting
There's a known issue/limitation with the dispersion code that I should probably fix. It's to do with the computation of the fresnel reflection term and the actual (waveelength-dependent) IOR for the wavelength as opposed to the base wavelength.

What if you increase cauchy B to a value such as 0.005?