<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande"><span style="font:12.0px Helvetica">the file </span>jit.gl.slab-float-readback.maxpat, found in the jitter 1.7 examples/render/slab folder causes max to crash. there isn't a render destination in the patch. what confuses me is that when i place a destination (a jit.window or pwindow) in the patch it still crashes. can someone tell me why?</p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px"><br></p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande">i'm intrigued to get a better understanding of the rtt fbo and ctt readback mechanisms, but am not convinced that this patch will provide the answers. can someone explain how these operate in jitter together with the advantages of each, or point me to somewhere that has a succinct explanation? </p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px"><br></p><p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px">as i understand these mechanisms:</p><p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px">
a) copy to texture (ctt), is a basic gl operation that copies the back buffer and and uses it to replace the previous texture that was rendered. </p><p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px">
b) render to texture (rtt) bypasses the buffer and renders directly to a texture. </p><p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px">c) the frame buffer object (fbo) has textures rendered to it before calling the rtt step, and this operation speeds up the overall rendering of a scene.</p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px"><br></p><p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px">presumably when a message is sent to jitter to use the fbo the set up for the object is injected into the rendering process. But, if this operation speeds up rendering why not use it all the time in place of other the other options? why does it need an explicit instruction? or are there occasions when using a fbo is pointless, eg when not using depth testing?</p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande;min-height:15.0px"><br></p>
<p style="margin:0.0px 0.0px 0.0px 0.0px;font:12.0px Lucida Grande">thanks</p>
<p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal 'Lucida Grande'; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal 'Lucida Grande'; ">
pelado<br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal 'Lucida Grande'; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal 'Lucida Grande'; ">
i'm on a mac powerbook, ATI radeon 9700, using OSX 10.4.11</p>