you can take a look at wes's accum shader (which mimics the erase_color functionality in a shader). linked here: https://cycling74.com/pipermail/jitter/2008-March/014225.html

it uses the previous frames texture in it's calculations.

-rob

Hi Rob,

Thanks for post.

I did almost the same way to calculate the frame difference. However, I want to have a speed boost by avoid the external transfer of a left texture to right.

Take a look of Wes' patch

What I want is like this,

Is it possible ?

yours, William

Quote: williamshome wrote on Mon, 14 April 2008 04:27 ---------------------------------------------------- > > Is it possible ?

not that i'm aware of, but i'm not a shader expert. i believe that's the nature of shaders, each pass only deals with the the pixel or vertex values at that moment in time. this is why they perform so fast. i don't really think passing the one texture will slow you down that much.

might be a better question for a glsl forum, but perhaps others know more.

I believe it is possible but we just do not understand how it works.

Would it be similar as writing back some data to the texture ? It has been mentioned by GPGPU ppl. Any glsl expert can help ?