[osg-users] Setting minimum hardward/drivers specs for osgVolume to OpenGL 2.0 era hardware

Robert Osfield robert.osfield at gmail.com
Wed Sep 17 03:37:28 PDT 2008

Hi All,

With the osgVolume project my plan was initially just to require
Texture3D so we wouldn't have to mess around with stacks of Texture2D
as a fallback.  Last night on pondering different elements of design
it occurred to me that all the rendering techniques of real interest
can only be implemented with shaders or on the CPU using race tracing,
there simply isn't a way to create a fixed function pipeline.  Since
the fixed function fallbacks will be very limited compared to the ray
traced versions it begs the question whether this limited
functionality justifies the extra complexity in providing fallbacks.

Personally I'm rather tempted to conclude that setting minimum spec
for osgVolume to be GLSL and Texture3D support (i.e. OpenGL 2.0 era
hardware) would be a reasonable thing to do.  If you are going to try
volume rendering then you need modern hardware anyway just to cope
with the demands on memory size and memory bandwidth, and all modern
graphics hardware supports at least OpenGL 2.0.

Would a minimum spec of OpenGL 2.0 be acceptable for osgVolume users?  Thoughts?


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