Re: [Opensg-users] Multipass Rendering with computation between passes

[Oliver Kutter]

Hi Dirk, Dirk Reiners schrieb: Hi Oliver, On Fri, 2005-08-05 at 11:59 +0200, Oliver Kutter wrote: Hi, I want to do some data (non effects) computation on the gpu by glsl with multipass rendering. I put the data on the gpu by textures. For the way back from the gpu to my application, I want to use an object (like a plane or a quad) on the framebuffer and I want to read the pixel values of this object. My first question: Is there a way to create an object on the framebuffer (in 2D or with parallel projection) like the ImageForeground object and set some shader on it? Or do I have to manage this manually? I think you have to do it manually, but I'm not sure I fully understand what you're trying to do. Ok, second trial to explain. I need an object, for that the fragment shader normally computes the material effects. But I don't want the material, I want data computation. Therefore I need an object (in 2D space), that has an exact size (e.g. a quad of a size of 512x512 pixels) on the framebuffer, so that the fragment shader computes exactly 512x512 fragments. Because I have 512x512 data entries to compute. If the object would be in 3D space, it wouldn't have an exact size of 512x512 pixels, because its size depends on the distance to the camera. After the fragment shader does its work, I want to get the data back to my application (thanx for the hint in the last email, I'll try it). (A new question: Can I use FBOs (probably manually) in OpenSG now?) I hope, now it's clear. Oliver ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Opensg-users mailing list Opensg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/opensg-users