[Sidefx-houdini-list] About sprite shader for particle

[chuong nguyen vien]

Hi,

Houdini already has a sprite shader and a sprite sop. In order to get a better understand how it works, I am trying to make a sprite shader from scratch. However, i don't know for sure about the way it really works. The sprite shader in houdini contains two node, one is the surface shader and the other is vm_geo_sprite which i guess is a geometry shader. Here is what i get confused:

-When we assign the sprite shader to a particle, how does it take into account the color of each particle i set with a color node ? What is the relation between them (the color node and the shader) ?

My guess it that, in the vm_geo_sprite node, when we put Cd in the attribute, so the vm_geo_sprite will know about the color of the particle (but internally, how  does it know ? Or exactly can we make a custom vm_geo_sprite node ?).
Then, the vm_geo_sprite node will override the color of the surface shader. But if works like that, then the surface shader is only used for determine other characteristic of the particle.

I will very appreciate for every hint about it :)

Chuong