Environment Fog, 3D Textures and Invalid Color

[vlado]

I've noticed I get that issue sometimes when I alter light intensities on multiple lights via the channel box. Sometimes a couple random ones will pick up "INF" instead of a valid intensity and result in nans/negative colors etc. Seems to happen frequently with sphere and IES lights, less often with others.

I've learned to only edit more than one light at a time via the attribute spreadsheet instead.

Worth a look,

--T

Thanks for the pointer - we will look into it. It's a different issue though and is related to the way we handle the inter-dependencies between the intensity/units/temperature attributes for the lights.

Best regards,
Vlado

[sebastiaaan]

Hey,
treyharrell, thanks for your suggestion. I looked into it and couldn't find any lights with INF as intensity, though.

Vlado, thanks for looking into it! That's good news. When will the next stable build be available and will your fix be included? Because I'm a student and just have access to the stable builds.

What I have also noticed is, that once the light cache retrace threshold (1) is enabled and you have hair AND SSS in your scene the render time (SSS Prepass) goes through the roof. Like from 2 hours to 14 hours for a close up. The render time is fine however, when I render each one alone. I don't know if this is normal or I have just put the wrong numbers in, since I couldn't find a lot of information on setting it up. Just thought I would mention it.

Cheers,
Sebastian

[vlado]

Vlado, thanks for looking into it! That's good news. When will the next stable build be available and will your fix be included? Because I'm a student and just have access to the stable builds.

Hm, it might be a while, but if you email me to vlado@chaosgroup.com, I can run a build for you. Or you can pipe those textures through a clamp node, this might help as well.

What I have also noticed is, that once the light cache retrace threshold (1) is enabled and you have hair AND SSS in your scene the render time (SSS Prepass) goes through the roof.

That's odd; do you have the "scatter gi" option enabled in the sss material?

Best regards,
Vlado

[sebastiaaan]

Hm, it might be a while, but if you email me to vlado@chaosgroup.com, I can run a build for you. Or you can pipe those textures through a clamp node, this might help as well.

That's odd; do you have the "scatter gi" option enabled in the sss material?

Best regards,
Vlado

Thanks, I will email you. This is great, since I have been struggling with this for a while.

Yes, the scatter gi option is enabled.

Kind Regards,
Sebastian


Just checked this again... it seems to be limited to her face, probably since there is the only hair. On her arm it seems fine. But it doesn't matter I'm just going to render it separately. : )

[sebastiaaan]

Hey Vlado,
Did you get my email? Or did you just not have the time to respond yet? There was a problem with the email servers the last days, that's why I'm asking... . Also, I haven't been able to solve the problem yet. In some renders everything is fine and in others the problem is there again.
Kind Regards,
Sebastian


I substituted all the mesh lights with normal ones, this seems to fix it for now.

[sebastiaaan]

Hey,

the Problem is gone (it seems). The Meshlights were the cause. However I can still force it, when I put in a Noise Amplitude, higher than 1.

Next question. Sorry, if this is getting quite long, but I'm still learning.

What do I have to do, if I don't want my fog to be cut off straight by the fog height value? I tried mapping it but it doesn't really have much of an effect (maybe I'm doing it just wrong...). I want a cloudy, wispy feel to it at the top.

It looks fine from a steep angle:


However, with a more horizontal angle, it looks like this:


Hopefully, it's done after this one

Kind Regards,
Sebastian

[vlado]

You could use a gradient ramp or something to fade the density. However if you look at the fog in the infinity it is always going to be a straight line unless you are a little bit inside the fog itself.

Best regards,
Vlado

[vlado]

P.S. Mesh lights were one of the problem; negative values in the Noise texture (when the amplitude is pushed beyong 1) was the other. They should both be fixed in the build I sent you.

Best regards,
Vlado

[sebastiaaan]

Hey Vlado,

thanks a lot! The build fixed it. Both issues.

I think I will have to find another solution for the fog, though. Unless someone has a great tip for me. I have a 3D solidFractal in the density slot already; I tried tweaking everything by now, however I can't seem to get the top broken up into wispy shapes.

Kind Regrads,
Sebastian

[vlado]

Like I said, raise the fog to include the camera...

Best regards,
Vlado

[sebastiaaan]

Hey,

the invalid color error is back, even with the new build. Once I try to precalculate Light Cache with 5000 subdiv with primary and secondary engine set as Light Cache, and set to fly-through, I get loads and loads of invalid color errors. When I try to reuse that precalculated LC I get black spots scattered through the whole scene. I tried isolating it, however had no luck, since it seems really random. There is no fog or 3D texture in the scene. Do you have an idea, what could be the problem?

Invalid Color



Kind Regards,
Sebastian

The strangest thing is, that single frames render fine, I even rendered about 90 frames, they were fine also. Should I send you the whole scene? (quite big)

[vlado]

The strangest thing is, that single frames render fine, I even rendered about 90 frames, they were fine also. Should I send you the whole scene? (quite big)

It will be helpful; otherwise I don't know what else might be wrong.

Best regards,
Vlado

[sebastiaaan]

I managed to break it down a bit and sent the scene to your email adress. : )

Kind Regards,
Sebastian

[sebastiaaan]

Any news on this? I fixed it using a frame from the beginning with the same settings for the LC file, i don't know however why this would make a difference. Would be nice to know what was wrong... .