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FabioMSilva
02-24-2006, 03:36 PM
hi. i just imported a bitmap to combustion as footage(the main intent of this is to know where to place my particle systems from combustion) and added some particles above it. Now what i wanted to do is extract just the particles with alpha to use on aftereffects or photoshop. Unfortunatly, if i turn off the footage "layer" thing the particles also disappear. Either way i'm not sure how i can just render the particles with the alpha :S

please help if u can:)

thanx in advance.
PetrolUk
02-25-2006, 12:16 AM
I just add a PAINT operator. Go into PAINT and make a fullscreen rectangle but make sure the channel is set to ALPHA (colour Black) rather than RGBA. Then just make sure this PAINT operator is below the PARTICLES in the workspace.

Basically it applies a negative alpha to your base footage and as the particles are on top they will retain their own alpha fpr your render.

Hope it makes sense, oh make sure that the rectange is set for ALL FRAMES
neogeo51
02-25-2006, 08:54 AM
My suggestion would be to create a new transparent solid layer and copy and paste the particles operator to that solid. If the particles are too dark or bright after that, set the opacity of the solid layer to 100% and change the color to black. Due to the alpha channel is completely opaque now, you can composite the resulting images with "lighten" or "add" in PS.
Hope that helps.
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