Hi Jason, If each Camera triggers the creation of RenderStage then the pre/post draw callbacks will be called once per Camera. As Mathias mentioned a Nested Camera doesn't trigger a creation of its own RenderStage, rather just reuses the existing one and doesn't override anything about this RenderStage.
Robert. On Fri, May 9, 2008 at 2:19 PM, Jason Ziglar <[EMAIL PROTECTED]> wrote: > Does this imply that the PreDrawCallback is only called once per render > stage? If I have multiple cameras, each with a separate callback, do they > all get called at once, or do they get called just each one performs it's > rendering? > > If they all get called at once, how would I go about having each one have a > function call just before they draw? I'm trying to update a set of textures > just before each camera performs a render pass, so they all use the same > shader, but with different textures. > > > > Mathias Fröhlich wrote: >> >> Hi, >> >> On Thursday 08 May 2008 20:00, Jason Ziglar wrote: >> >>> >>> I've got a camera which is part of my scene graph, and for some reason >>> it doesn't appear to be getting called to render part of the scene. >>> >>> The camera is set to be a NESTED_RENDER, and has a PreDrawCallback. The >>> callback never gets called, nor does it appear to have any rendering >>> output that I can see. I have tested to verify that the camera is a >>> child of the root node, and the primary camera and a PRE_RENDER camera >>> are both working as expected. Is there any subtleties to getting a >>> NESTED_RENDER camera to activate? >>> >> >> Well, the pre draw callcack only gets called when you get a new render >> stage through that camera. And this does *not* happen for nested cameras. To >> get a render stage you will need to set the camera type to pre render or >> post render. Then the callback gets called. >> >> There are much more properties in the camera that are a noop when the >> camera does not lead to a new render stage in the rendering backend. The >> clear mask and clear color for example. I do not know which ones exactly >> without looking into the code, but if you have a nested camera you must be >> extremely careful with the values you try to use in the camera. Many of them >> will only have an effect if the camera os *not* a nested one. >> So, if you know the internals of the rendering backend well, the camera >> works relatively intuitive. But if you don't, it's very hard ... >> >> Good luck >> >> Mathias >> >> > > _______________________________________________ > 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
