Velocity as a map

[Steve_Green]

Hi,

I was watching a nature programme about bioluminescence last night, and there were some great scenes with water being disturbed, lighting up and then dimming as it settled.

It got me wondering how you might achieve that with PhoenixFD - there's the motion vectors render element, but was thinking more as a map so it could light up the rest of the scene.

Thanks,

Steve

[Svetlin.Nikolov]

Hey - there's the Phoenix Grid texture - https://docs.chaosgroup.com/display/...oenixFDGridTex. You can use to extract any grid channel as a texture and use it for rendering or as a map for controlling another simulator. You just need to export to the cache files the channel you are going to use via the texture. There is also the particle texture - https://docs.chaosgroup.com/display/...xFDParticleTex. It uses the positions of particles to create a grayscale map you can also use for shading.

Maybe you can use a grid texture by the Speed channel, multiplied by a particle texture using the liquid particles. You could plug that as self-illumination of a material for example. You just have to watch out for the range of the speed channel - you can see in the Simulation rollout the min and max values of the Speed channel - usually they would be in the vicinity of few hundred, so you might need to multiply the texture by some very small number before using it as a color.

[Steve_Green]

Great, thanks! Was looking at the grid texture but wasn't sure what values might need tweaking!

[flipbook]

Ha.. Ihad the exact same thoughts of doing this when watching the same programme on bbc last night ... maybe when projects subside .. who knows when that will be!

[Steve_Green]

Haha, yeah was pretty hypnotising!