hi michal
using [pix_alpha] works, but it will eat much of your cpu. otoh [colorRGB] , which also is able to render the alpha-channel, is calculated on the graphicscards processor. in order to process also the alpha-channel, you need to put an [alpha]-object into the chain. once you have a picture, where only the person is visible, you can apply this texture on as many geos (e.g [square] or [rectangle] etc.) as you want.
roman
----- Original Message ----- From: "michal panaak" panaak@gmail.com To: pd-list@iem.at Sent: Monday, June 05, 2006 3:02 PM Subject: [PD] noob question: alpha channel multiplication
hi pd people!
i'm working on this project:
the basic idea is to create an interactive installation, where anyone could move around with a bluescreen behind his back, while in front of him, there would be a projection screen with a huge crowd of clones of oneself facing the performer..
i need to capture a person in front of a bluescreen, create alpha channel of the person, multiply it and import it into a picture (for example a picture of some plaza) so that it would look like a regiment of clones moving around in a grid.. in perspective..
i think i'd need functions pix_alpha / pix_chroma_key / pix_mask for the alpha channel processing.. and then some other GEM functions to multiply it and create a grid inside a picture.. but i'm not sure exactly how..
all i ask is to kick me in the right direction..
-mp-
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