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DrPowers

particle system

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I''ve been working on a particle system... a missle contrail specifically. My question is this. The way this particular partical system works (WildMagic) You create a texture with an alpha channel. You create a # of particles with properties size, and location. You assign the texture to the particle system. My problem is this: How do I change the individual alpha channels of particles for example: as they get farther away from the start they become more transparent

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well you can simply use the vertex.diffuse colour property, or you can set custom blend values on your render call, or you can use a vertex shader to alter the diffuse property, or you can do it with the ps, or you can have a texture animation of cells with increasing alpha.

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Given a start colour, an end colour, and the lifetime of a particle, I calculate a colour "offset" that you add to the current colour each frame until it would reach that end colour at the end of it''s lifetime.

- Ben
[benlog.org] [Project 0 A.D.]

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I kindof cheated but I figured out a good way thats faster than mapping them procedurally.

I'm imputing a greyscale bmp of my smoke and using the red channel (or any of them for that manner) as the alpha channel. Since this maps directly with the formation of the clouds it works.

---- sorry wrong thread that I started....

This problem isnt actually fixable with the current system that I have. I found out that this system infact can only assign a texture to all the particles and not individually.. as in they will always have the same texture..

This is becuase this system uses a single trimesh instead of multiple ones for each particle

[edited by - DrPowers on April 23, 2004 11:38:58 AM]

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