Particle Normal pass for relighting?

[poppy]

Hi there!

How could I render the normal pass for particle overall volume? (not just for individual spheres)

something like this attached image

Thanks!

[poppy]

sorry forgot the file

[mightcouldb1]

That is a fluid simulation, not particles. It is rendered using red, green, and blue lights then you can extract the channels in your compositor and do the lighting that way. If you want even more control, you can render your lights to layers in an EXR file, allowing you to have more than 3 lights and an Alpha channel.

[poppy]

That is a fluid simulation, not particles. It is rendered using red, green, and blue lights then you can extract the channels in your compositor and do the lighting that way. If you want even more control, you can render your lights to layers in an EXR file, allowing you to have more than 3 lights and an Alpha channel.

thanks,

so the same method should work with particles, right? How should I place my light manually? I mean, which color to which axis?

[lukeiamyourfather]

thanks,

so the same method should work with particles, right? How should I place my light manually? I mean, which color to which axis?

Typically each color channel is associated with a light serving a specific purpose (key, fill, back, etc.). The colors don't have to correspond to an axis in the scene. Really though this is an old trick that isn't necessary anymore. Using OpenEXR you can stuff full renders from each light into their own AOV/channel/layer (whatever you want to call it).

[bhaveshpandey]

If you want to get normals for particles, you will have to create a normal

attribute on them.

Typically if you have particles from a flip fluid sim, you'd want to take the gradient of the surface field and then use it as

Normals for your particles.

You could use the Gas Field To Particle dop for this along with Gas Analyse dop (which would get you the gradient of surface field).