Hey Guys,

Sorry about the convoluted title. Please allow me to explain.

I am doing a tutorial where one set of particle pours into another one with higher density causing an “oily” effect.

The procedure is that I merge these two particle systems, run the simulation, put a null at the end, import the result into another module, cache it and then use the cache to play around with materials, lighting etc.

At this point the tutorial goes to using redshift, which I dont have and then I kind of lose the plot.

My question is:

When I merge the two particle systems it retains only one Cd attribute for both systems. I tried several methods with my limited knowledge to rename, or a means to separate the two Cd attributes but they did not work. Can anyone be so kind as to shine a light on this? What I would ideally have is two color controls, one for each particle system, after the cache where I could change colours or, even better, apply different shaders to the different particle systems.

Also, and this I am asking asking before having taken a proper look, is there a shader that deals exclusively with particles? I dived into the principal shader an found little to deal with particles.

Many thanks,

Richard

- if you simmed with 2 different sources, you already have groups containing individual streams of particles from both sources

- you don't need 2 Cd attributes, just have your controls either change Cd per stream group or assign different integer/float value per source/stream and then remap either by switching colors using the integer attribute or of it's float and you mix between the colors you can also plug it into ramp

- all Mantra surface shaders deal with particles, particles are either shaded as discs or spheres, however you are mentioning Redshift so not sure exactly if you have any issues, but there are object properties for all renderers that can specify how are particles rendered

Hi Tomas,

Thanks for the help.

- you don't need 2 Cd attributes, just have your controls either change Cd per stream group or assign different integer/float value per source/stream and then remap either by switching colors using the integer attribute or of it's float and you mix between the colors you can also plug it into ramp

Would I do this with an attribute wrangler after the cache file? or diving into the shader? To be honest I did not understand your explanation as to how I would set up these controllers and how I would separate the stream groups.

BTW: When I plug any shader on the sim, it certainly recognizes the two groups. But it one is black and the other one is white problem being that I cant put them change the colours.

I have tried plugging a ramp into the base color, but then it overrides the “use point color” attribute on the shader's surface tab and “flattens” the sim (meaning it becomes only one color). I tried plugging several things into the ramp's entry but nothing seems to work.

In other words I guess what I would need is to make the ramp understanding the colour coming in from the different stream groups,and then overwrite them. Or how to use these groups to assign different colors, I think you explained it above but I didn't understand how to do it, or code it.

Hopefully this makes sense :-D. Thanks anyway.

R