Always re-sim after chnaging RGB channels for liquid colour mixing?

[JD3D_CGI]

Quick question: I'm mixing liquid paint colours using the RGB channel. Do I really need to re-sim every time I want to change a colour?

why can't just changing the colour change the data throughout?

[Gosho.Genchev]

Hey there ! Assuming you're using Maya:

The output of the PhoenixFD Texture is a regular color. You can drop a Color Correct node between the Texture output and the Material input and edit the colors there.

[George Barzinski]

Yes and for Max:

[JD3D_CGI]

Thanks guys! I will give it a try!

Although I am mixing colours, so I am not sure how a colour correct will look at just one of the colours?

[George Barzinski]

Ok, so you can change up to 3 colors remapping RGB channels. In the scene there're 3 sources with red, green and blue RGB colors. After that, every single color is remapped using a color correction (see the yellow marker) and the results are set to Blend channels 1, 2 and 3 of the VRayBlendMtl. There are 3 color corrections for each channel and they are set to Red, Red, Red, second one to Blue, Blue, Blue, and third one Green, Green, Green.

[designit_idea]

A question in relation to this. Is it possible to use the PhoenixFD texture, to fx blend colors, when rendering the liquid particles as fx points with the PHX shader. Looking to make some cool swirly unicorn grains for some motion graphics stuff

[Gosho.Genchev]

Hey, designit_idea , are you using Max or Maya ?

I spent some time trying to figure out a way for you to do this and managed to find a solution for Maya only.
I'm attaching a video as decent screenshots would take quite a while. Hope you don't mind.

Here's how this works:

The Phoenix simulator generates a bunch of particle groups that act as 'containers' for each type of particle - liquid, foam, splashes, mist, etc. You can select a particle group and tell it to output its particles to an nParticleShape node which you can then render as regular particles.
The RGB channel of the simulator is piped to the nParticles diffuse color through a PhoenixFD Grid texture. The Grid texture is used to read the value of a specific channel of the grid and output it as color data. It acts like a 3d texture - if the particle is near a certain voxel of the grid with an RGB value of [0, 0, 1], it's going to inherit that color. When it moves to another voxel, it's going to inherit another value. The same applies for regular poly geometry, too.


As a side note - the density of the liquid particles depends on the resolution of your grid. Therefore, if you want more particles, you'll need to increase the resolution. This restriction does not apply to foam.
I would suggest emitting foam and using the workflow from the video with the Foam particle group rather than the liquid one. That way the density of your particles can be controlled independently of the grid resolution. If you choose to go down this route, here's a couple of suggestions:
1. Enable Particles from the Phoenix liquid source node and set the type to foam.
2. Enable Foam from the Foam tab of the simulator and set the Foam Amount to 0 - this way only the particles emitted from the liquid source will be used.
3. Hide the automatically generated Foam shader if you'd rather not render the foam using the Phoenix FD Particle Shader.

[JD3D_CGI]

Ok, so you can change up to 3 colors remapping RGB channels. In the scene there're 3 sources with red, green and blue RGB colors. After that, every single color is remapped using a color correction (see the yellow marker) and the results are set to Blend channels 1, 2 and 3 of the VRayBlendMtl. There are 3 color corrections for each channel and they are set to Red, Red, Red, second one to Blue, Blue, Blue, and third one Green, Green, Green.

Thanks mate, I am just now getting around to this, as the client wants to go to stage to.

I am working under the assumption that my source colour nodes need to be full Red, full blue, and then full green?

[Svetlin.Nikolov]

Indeed - having the color components at full would be the best

[JD3D_CGI]

That works a charm! cheers guys!

Will there every be a time when we can have the colour emitted be from a texture on the source object?

[Svetlin.Nikolov]

Yay!

You can emit color from texture right now - you just have to put a texture in the RGB instead of a plain color

[brandon_white]

I have a related question, is there a way to use a wetmap to produce multiple colors? I have a sim where multiple paints colors are thrown on a white wall and I need the wetmap to correspond to each of the paint colors so that the correct color is left on the wall as the paint drips down. But so far I've only been able to get the wetmap to use only one color.

[georgi.zhekov]

I have a related question, is there a way to use a wetmap to produce multiple colors? I have a sim where multiple paints colors are thrown on a white wall and I need the wetmap to correspond to each of the paint colors so that the correct color is left on the wall as the paint drips down. But so far I've only been able to get the wetmap to use only one color.

Yes, you just need to get the latest Phoenix version - 5.22

Then in the output rollout you will need to enable the RGB channel for the Wetmap particles and sim again.