Color Change (Color Mapper) Tracer

[cyrilrueg]

Hi! My question would be how can I change the color of the Tracer so that it takes the data from the Color Mapper here? Thank you very much

https://we.tl/t-69YbnMQS6p

[Dr. Sassi]

Hi cyrilrueg,

Thanks for your file!
.

The Tracer can't take the color from the Particles.

It can be done with a little workaround. Please have a look here:
https://stcineversityprod02.blob.core.windows.net/$web/Cineversity_Forum_Support/2024_PROJECTS_DRS/20240724_CV4_2024_drs_24_PAtc_01.zip

To get this visually established, a few steps are needed.

• Set up the colors and the Particle animation as you need.
• Cache it
• Trace the path (Play mode single)
• Tracer, "Current State to Object", to harvest on the last frame the spline
• This spline goes into a Sweep set up
• Also, here, Current State to Object (optional) and use a Color Vertex Tag on it
.
• This Color Vertex Tag is set to Transfer (fields), and the Cached Particle Group is placed in it.
• Set the Freeze to "auto Update".
.
• Set up a material with the Color Vertex map.
• Use the Vertex Tag Color output with a Ramp to set the Opacity; if it is black, it is transparent.
.

The Particles might be seen in the Rendering, use them or switch the group invisible (Art Direction call)

I hope everything that I did not mention is in the file.

You might notice that the Particle Radius in the Vertex Map Field area needs a certain radius to fill the whole "path". This might affect close neighbor paths. I have no idea currently for that. I hope it melts away (visually) if you use "Bloom" in your render.

All the best

[Dr. Sassi]

P.S.: here is a quick demo

https://youtu.be/Hd3rAcNRg3M