On Jan 7, 2008 9:58 AM, forest37 <[EMAIL PROTECTED]> wrote: > What does fastPath mean? Is it related to VBO?
OpenGL fast paths are the ones that are fast... i.e. deliverad to OpenGL in the way that is fastest in terms of dispatch into the OpenGL fifo, and fast for the OpenGL driver to pass to the GPU and for the GPU to process. Fast paths are based of vertex arrays, and draw arrays and draw elements calls. Slow paths are when you have to use glBegin() glVertext(..) glEnd() calls to build up the geometry. All vertex indices use forces the usage of slow paths. > There is a sentence "if (_vertexData.indices.valid()) _fastPath = false;" > in the function Geometry::computeFastPathsUsed() > It seems that i can't use fastPath when i use setVertexIndices(); > > I just want to use Vertex_Buffer_Object,what should i do? OpenGL doesn't support vertex indices with vertex arrays/ vertex buffer objects, the only way to do it is to drop down to using glBegin etc, i.e. the slow paths. So if you want fast paths absolutely never ever ever used vertex indices. Vertex indices are there in the OSG purely for backwards compatibility and are not something I'd recommend usage today. Robert _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
