View Full Version : how to emit particles from the illuminated part of the surface

04 April 2003, 01:32 PM
Well my subject says it all...
I know I have to use surfaceLuminance node and somehow connect it with the texture rate attribute of the emmiter but I can't figure out how...
Final product should be that only illuminated parts of the surface emmit particles...

Maya Ayanami
04 April 2003, 04:05 AM
I dont know. I think you will have to do some mel there.

04 April 2003, 06:44 AM
When you set up the Emit from surface -> texture emission attributes , there is a checkbox under there that says "use luminance"and "emit from dark"

That should do what you are looking for.

04 April 2003, 09:11 AM
if you really want to emit particles from the lit side and not (as sheep mentioned) from the bright areas is a texture you will get a small problem with the surface luminance node..
in order to know where the surface luminance is, maya would need to render the object.. so maya wont be able emitting particles from that object in real time..

but you can still write out the surface luminance by baking the texture. that file you will be able to use for the emission..



edit: when trying to bake the map, be sure to check "bake shading group lighting" ind the options from convert to file texture. otherwise the result will be black :)

04 April 2003, 08:07 AM
You will either have to bake the light or write mel or look at
they have written a script that does what you want look in the examples.

I would like maya to be able to do that without a script though....

Mads :)

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