Animation: re-render single Frame_ Material of Hedge changed

[christian_schneider1]

Hello Guys,

I'm currently doing an ANIMATION. When I rendered a single frame again, the color of certain objects has changed.
Both, Hedge and pebbles have a MultiSubTex material. Gi was cached previously. And all Frames were fine.

The renderprocess was divided into two parts because of a crash over night. I noticed afterwards that I forgot to render a single frame, which i wanna render now.
But unfortunately the Colors of hedges and Pebbles has slightly changed. I rendered the final pass with Teamrender, respectively via distributed Rendering.

Is there a way to rerender this single frame without changing the behavior of the MultiSubTex?

I've attached 2 frames ( changing of color is more obvious when you see the entire animation) and settings of my materials with MultiSubTex.

Thanks for help in advance.

[deyan.hadzhiev]

Hi christian_schneider1, unfortunately, due to the the option you were using in MultiSubTex ("Random by Render ID"), it might not be possible to achieve the same color. The problem with Render ID used for randomization is that it is not stable between renders and you will likely get different results on each render. Only very simple scenes might produce the same render ID, and it is still uncertain.
Sorry for the caused inconvenience, we will be adding additional info about the risks of using this option in the documentation.

[christian_schneider1]

Thanks deyan.hadzhiev for your answer. Is there an option in the settings that is better suited for animations? Or does it generally not work?

[deyan.hadzhiev]

Is there an option in the settings that is better suited for animations?

You can use any other of the composite options to achieve stable randomization across animation and multiple renders, depending on what you want to achieve. To achieve per object randomization, you can use the "Random by Node name" and the "Random by Scene Name" options, and also if the objects you need using the randomized textures are instanced (from Cloner, Chaos Scatter, or other Multi-reference type), you can also use the "Random by Instance ID", to achieve per-instance randomization. The rest of the "Random by..." options are for finer control over the randomization using user attributes, polygon selection or object IDs.

Or does it generally not work?

The problem is just with the RenderID, because this render ID is generated internally by V-Ray and the order of generating these is not guaranteed to be the same, especially after we added the optimization for faster geometry compilation back in V-Ray 6.1. We will probably be changing the default options when a new MultiSubTex is used to avoid the RenderID for this reason.

[christian_schneider1]

Thank you for your effort.
I haven't really tested the individual options of randomization at all. So I'll try out your suggestions. I think it will be fine

Best regards