Forums > Jitter

Frame difference in open gl?

October 3, 2009 | 10:24 pm

I am trying to emulate this effect in open gl:

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Just a simple frame difference (could be any op, but I’m used to using


October 4, 2009 | 7:31 pm

because of the way jitter copies the matrix to a gl texture, you need to store the previous frame in a separate matrix object.

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October 4, 2009 | 11:45 pm

Thanks, that does make sense, but unfortunately I forgot to mention that it is within an effects chain and is in the middle of a few gl textures already, so it is not coming in initially as matrix data. i ended up ripping something out of a wake-gl effect someone on this board had helped me with and just tossed some blurs in the signal chain and that seems to slow it down enough (or something like that) to get the frame difference…here is what it looks like within the signal chain..i’m doing different mixing to achieve different effects with feedback and the like..changing the datatype created some really interesting results, but some changes would just crash the texture and I’d have to close and re-open my patch:

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October 5, 2009 | 4:49 am

I think this is what you’re looking for.

Andrew B.

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October 5, 2009 | 12:15 pm

Apologies andrew, but I’m confused..I think you just posted the exact same thing I posted in my first post on the thread


October 5, 2009 | 5:01 pm

How embarassing! Here is what I meant to send:

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October 5, 2009 | 5:10 pm

ahh..i feel like i tried at at one point but I must’ve done something wrong..and then i assumed that a gl_texture wasn’t a list in the same way a matrix is a list, which was probably a silly assumption..but yes..that works exactly the way i wanted, thanks!


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