Re: [osg-users] Question about osg::Fog and RTT setups
Hey Robert, I have classes that I instantiate that use GLSL, but are not automatically enabled on the scene graph. Is there a way to use RTT and PIXEL_BUFFER setup that won't break osg::Fog? What I mean is, if I don't instantiate the GLSL objects, will osg::Fog remain intact in this type of setup? If you think so, what would you guess might happen if I create and then destroy these objects, assuming proper cleanup? Thanks pal, John -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Osfield Sent: Thursday, June 19, 2008 12:14 PM To: OpenSceneGraph Users Subject: Re: [osg-users] Question about osg::Fog and RTT setups Hi John, If you are using GLSL then osg::Fog/glFog will only provide the inbult fog uniform values will be available to the shader, but no fog will be applied unless you do something with them nothing will happen. If Fog is being applied when you are expect to that a subgraph is using GLSL then it suggests that GLSL is not being used for some reason. In you case you suggest the RTT Pbuffer you are seeing Fog, so perhaps the Pbuffer context doesn't support GLSL, or perhaps the contexts aren't being extension/manged correctly on the OSG side so that shaders aren't being applied correctly. It may also be easily a driver bug, trying your setup on different machines/drivers would help test this. Having never tried your particular usage combination I can't really provide any insight to way it's not working. As in my previously reply, I can't really do anything without a bit of code to test that reproduces the problem. Robert. On Thu, Jun 19, 2008 at 4:59 PM, Argentieri, John-P63223 [EMAIL PROTECTED] wrote: All, Why is it that osg::Fog, and maybe glFog(), work as expected in RTT setups if FRAME_BUFFER_OBJECT is chosen as the RenderTargetImplementation on your Camera, but if PIXEL_BUFFER/_RTT are chosen, you must re-load the scene? I think that people are under the impression that when GLSL shaders are used, glFog is broken, but that's not true. I think that if the osg::Fog is applied ( with Fog options ) to the Scene before setSceneData() is called, you will get fog, even in PIXEL_BUFFER type setups. BTW I have a GeForce 6 series on my box. John ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about osg::Fog and RTT setups
Hi John, I have classes that I instantiate that use GLSL, but are not automatically enabled on the scene graph. Is there a way to use RTT and PIXEL_BUFFER setup that won't break osg::Fog? What I mean is, if I don't instantiate the GLSL objects, will osg::Fog remain intact in this type of setup? osg::Fog uses the fixed pipeline fog functionality. If the nodes below where you use osg::Fog have no shaders attached/enabled, osg::Fog will work just fine. If you have shaders, they must implement fog themselves, which is not difficult Post if you need pointers (I did that recently myself) or get 3DLabs' ShaderGen program from http://www.mew.cx/glsl and generate shaders that replicate glFog. ShaderGen is a neat tool that can generate a shader set that replicates the full fixed pipeline functionality (if you need that). J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Question about osg::Fog and RTT setups
Hi John, If you are using GLSL then osg::Fog/glFog will only provide the inbult fog uniform values will be available to the shader, but no fog will be applied unless you do something with them nothing will happen. If Fog is being applied when you are expect to that a subgraph is using GLSL then it suggests that GLSL is not being used for some reason. In you case you suggest the RTT Pbuffer you are seeing Fog, so perhaps the Pbuffer context doesn't support GLSL, or perhaps the contexts aren't being extension/manged correctly on the OSG side so that shaders aren't being applied correctly. It may also be easily a driver bug, trying your setup on different machines/drivers would help test this. Having never tried your particular usage combination I can't really provide any insight to way it's not working. As in my previously reply, I can't really do anything without a bit of code to test that reproduces the problem. Robert. On Thu, Jun 19, 2008 at 4:59 PM, Argentieri, John-P63223 [EMAIL PROTECTED] wrote: All, Why is it that osg::Fog, and maybe glFog(), work as expected in RTT setups if FRAME_BUFFER_OBJECT is chosen as the RenderTargetImplementation on your Camera, but if PIXEL_BUFFER/_RTT are chosen, you must re-load the scene? I think that people are under the impression that when GLSL shaders are used, glFog is broken, but that's not true. I think that if the osg::Fog is applied ( with Fog options ) to the Scene before setSceneData() is called, you will get fog, even in PIXEL_BUFFER type setups. BTW I have a GeForce 6 series on my box. John ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
