Random value for Particle System trails material in Unity

Hi, I need to make a random value for trails in a particle system so that the picture does not repeat in multiple particles. In the standard material for particles, I do this through custom data, but for trails it is not available for trail materials, tell me what to do?
So I have a value(or W/T value from UV) in the material that I need to make random for each particle trail.
Any ideas?:sweat_smile:

use the WP position in your trail shader to give the UV an offset.

Wow, thanks, sometimes I forget about such elementary things :sweat_smile:

But how can I get float value from WP position gradient? WP position instead of UV (or + UV) gives the wrong tiling.
P.S. I also understood one thing, there will be no randomization from WP, since the value will depend on this world position itself.

I think this is a very important issue for VFX artist, but is there still no solution?

Custom Vertex Streams does not work for trails, however, vertex colors does. My suggestion is to use either channel RGB or A to drive some shader parameter in the trail shader. This comes at the expense at sacrificing channels for that feature, so its not perfect but I expect it would work

To make the value random: Set parent particle color to Random and enable Trail color inheritance

Yes. The solution is to make random vertex color(from white 1 to black 0) in main module. Vertex color will make random texture position if you add it to UV.

Thank you for response!
In reality, I am also giving first aid with this imperfect method. every time.
I’ll have to wait another 10 years to get the perfect way.