Getting stepping in Color and density animation in Fog

[Mark]

Hi Dr Sassi,

Using RS Environment, we are animating the Emission Color and thickness using Camera under Ray contribution of fog to simulate morning fog to clear daylight. After looking this up on the internet and trying different render setting we we can not eliminate a flickering effect in output renders when playing them back.
The color will say even then will jump fairly dramatically from one frame to the next. You can see in the image I have done a split screen of 2 consecutive frames. I have uploaded a striped down project and one material texture needed to duplicate the issue. Do you know anything that might eliminate this drastic jump in color from frame to frame?

If you render from this project starting at frame 110, you should see the issue by frame 128.

https://drive.google.com/file/d/1JuCYkcAqKTndRO5JVNxrxIKO72amScsl/view?usp=sharing
https://drive.google.com/file/d/1acRxB8HCUZxGGz2vP2L1u5jdCPYAgTbv/view?usp=sharing

Thanks Mark

[Dr. Sassi]

Hi Mark,

Thanks for the file, and using Google.

Update after investing another hour into it.

Certainly, there is an interaction between fog emission and camera rays. Even if I turn off animation for one or the other, I can see that effect. The question is, why does this appear? The answer is surely in the many micro and random animations, sometimes just a few degrees or rotation, a slight change in opacity, and many other things that are not in your description of the scene that might, in concert, create this effect.

I can't judge if the animations are done accidentally, as the overall effect seems too small, but you might have reasons.

The scale, especially the long animation duration, often has little change, over 10 minutes worth of rendering in one shot.

My current result (Guesses?), the mixture of all keyframes set to materials, lights parameters, and whatnot create an effect, while others take it momentarily away. Camera rays are look like distant based How much they receive while the "fog is there anyway, and the background plane is rotating, while colors are animated as well. The question is, can the effect you are after not be produced in a simpler direct way.

I need a full description of every part that is animated and why; otherwise, I'm just guessing if it is a sloppy project setup or scientific precision. I don't know what the base is. I sure mean not to create any insult here if that is even assumed remotely. it is not.

It is stable if I set up a test scene with a few non-animated parts.

So, what to do? Reduce the elements to the minimum, and check if all animations are needed. Let me know if you need to have the backplane perpendicular to the camera,
Delete any animation that is not needed.
My best description of that problem is the Interference effect of multiple sources.

I missed some textures, so I'm not sure if I saw what you saw.

My best wishes

[Dr. Sassi]

P.S.: I have very little problems when I convert the Project scale to 1 : 0.0001.
Of course things change then.
As mentioned, I know too little about the problems, to know what is needed.

[Mark]

Thank you I will give that a try!

[Dr. Sassi]

Hi Mark,

I hope any of these will give you the results you are after. In a nutshell, I think several animated parameters work against each other at the frames around 122 and 128; which one is crucial and is not for me to decide.

CV4_2025_drs_25_RSsf_01.c4d
Place it in the project folder. I get no color flickering.

I haven't figured out the Fog height of one, affecting so anything around or below the Horizon, but the scene is based on anything but "floor" level.

Perhaps try to create the "fog" with a light that doesn't have any diffuse but some volume. But yes, I have not gotten any information, is there a sketch somewhere?

Since this is based on an Edu License, what is the Curriculum, or what support do you get from the instructor?

Enjoy your weekend

[Mark]

Thank you for the additional info. I will take a look at what you sent when I have a chance. Don't know what you mean by a "sketch"?

Also, I am not a student, I work for a nonprofit creating materials to support their educational program.

[Dr. Sassi]

Hi Mark,

I do not access the data of who got an educational license and where it is used. Perhaps it is time to explore that more. Typically, my conclusion is that the licenses are active in an environment that is fully covered with people who are savvy with instructional design and/or learning theories, as well as subject matter experts in visual arts.

While I sometimes get questions here that make me wonder how much some institutions instruct their students… My target here is to support any artist and ensure that every artist investing time to learn is treated in the best way. I assume that is your target as well.

Thanks for clearing your use here; that allows me to see your ideas a little bit more clearly, but it is far from obvious, as many parts in the file are missing, going by the materials in the file, etc.

With sketch, I mean a small drawing that introduces the complexity of the idea, an outline. That kind of information transfer should be natural for you as you create things for others. I wish I would get a storyboard for complex setups.
Here, I am interested in seeing what you need and providing the best solution.

Since I have done this for over two decades, in fora, or hands-on Coast to Coast here, I know that the solution is often many steps before the problem starts. This means I need to know more – not to patch a problem but to know the desired result and take it from there instead of finding a workaround for a setup that produced the problem.

All that being said, thanks to the support of people who might otherwise have no chance to learn it (I assume that is the idea of the non-profit). This is very generous of you!

So, let's find the best way to get this working.

Have a great start to your week.