<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body><div>Use, format RGB32 instead of RGB for your framebufers.</div><div>++</div><div><br></div><div><div style="font-size:100%">Jack</div></div> <br>Py Fave <pyfave@gmail.com> a écrit :<br>first thanks both for your help.<br>i was tired yesterday evening.<br><br>jack , i have a problem with your patch.<br>i had already similar problems before, that's why i wanted to use some<br>shader in the feedback chain .<br><br>it works ok BUT with very long feedback ( 0.999 alpha ) values i get a<br> ghost image,<br>the point never diseappears( because perhaps of a bad approximation in<br>opengl ) .<br>ie : color 1 1 1 0.995<br>leaves traces<br>is that a problem with my graphics card ? i don't think so .<br>i join a clumsy correction test , with makes things flicker a bit too much .<br>do you have a better workaround?<br><br><br><br>2013/10/2 Jack <jack@rybn.org>:<br>> Le 02/10/2013 20:10, Py Fave a écrit :<br>>> Hello list ,<br>>><br>>> i'm currently trying to understand a bit more glsl ,<br>>> and am tearing my hairs<br>>><br>>> i have a scene with some moving geometry (torus)<br>>> on this geometry i use successfully a simple shader to plot a moving circle.<br>>><br>>> Then<br>>> i try to make the classical feedback effect , but i need to use glsl<br>>> because i want to control precisely the adding of the image at time<br>>> and at time+1<br>>><br>>> here is the feedback shader i try to use .<br>>> ----<br>>> uniform sampler2D tex1,tex2;<br>>> uniform float motionblurstrenght;<br>>> vec2 coord = gl_TexCoord[0].st;<br>>> void main()<br>>> {<br>>> vec4 t1 = texture(tex1, coord);//new frame<br>>> vec4 t2 = texture(tex2, coord);//acumulated frame<br>>> gl_FragColor = vec4(t1.r);<br>>> float r = ((1.-motionblurstrenght)*t2.r) + (t1.r);//motion blur<br>>> gl_FragColor = vec4(r);<br>>> }<br>>> ----------------------<br>>><br>>><br>>> do you have a clean example or hints on how to implement this ?<br>>> i am currently fighting with gemframebuffer and pix_texture<br>>> and rendering order and texunits .<br>>> and i feel i'm missing something ..<br>>><br>>> i would like , if possible to keep this as an effect i can turn on and<br>>> off , without modifing my current gem chains .<br>>><br>>> i think i need two gem chains ,one early and one at last in the frame<br>>> drawing chronology , but i can't make it though i tried a lot<br>>><br>>> any help appreciated .<br>>><br>>> Pierre-Yves<br>>><br>>> _______________________________________________<br>>> Pd-list@iem.at mailing list<br>>> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list<br>><br>> This example could help, see attached.<br>> ++<br>><br>> Jack<br>><br>><br>><br>> _______________________________________________<br>> Pd-list@iem.at mailing list<br>> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list<br>><br> </body>