Thanks again Robert, I'll do some testing with vertex duplication and see if I can't make it work for me.
robertosfield wrote: > On 15 January 2014 20:40, Ethan Fahy < ()> wrote: > > > Thanks for bearing with me Robert, I do realize that there has been much > > discussion over this topic (I have spent hours trying to understand it all > > but OSG is the only exposure to OpenGL that I've ever had so trying to > > understand it all is tricky for me). > > > > You mention using the osg_deprecated to tide me over, but I'm wondering > > what is the more appropriate long-term solution. To be clear, I don't need > > to support any existing geometry that contains BIND_PER_PRIMITIVE (i.e. I > > don't need to use fixDeprecatedData(). What I do need to do is to be able > > to create new osgGeometry objects with osg3.2 and future versions of osg > > that allow me to have the end-effect of coloring each primitive > > individually. Now, if I am understanding correctly, what I will have to do > > when creating new geometry is to only put a single primitive in each > > primitiveset and use BIND_PER_PRIMITIVE_SET. My understanding is that > > BIND_PER_PRIMITIVE_SET is supported in OpenGL and that this will not be > > deprecated any time soon. Do I have this more or less correct? > > > BIND_PER_PRIMITIVE_SET is OK to use, it can be used relatively efficiently > with all versions OpenGL. It could result in lots of OpenGL calls though as > you have fine grained primitive sets that each have to be sent to OpenGL. > Performance witse this is still be more efficient than what the OSG was > having to do with BIND_PER_PRIMITIVE though as here it had to duplicate data > and reorder before sending it OpenGL. > > > The route with best performance on modern hardware would be to duplicate the > vertices and use per vertex colours. This route would allow you to use a > single DrawElementsUByte and lead to less OpenGl call overhead, which > typically saves more than the cost of the extra data. > > > Robert. > > ------------------ > Post generated by Mail2Forum ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=57893#57893 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
