Jeremy, Very cool to see this OpenSceneGraph support for NV_path_rendering.
I hope you'll explore the ability to mix 3D and path rendering within a depth-buffered perspective scene as discussed in the "Mixing Path Rendering and 3D" whitepaper. Any CUDA-capable NVIDIA GPU under Windows or Linux can use NV_path_rendering with Release 275 drivers or later. A few suggestions for your osgNVPR::Path object: * Consider having the "_colors" be a path "paint" object. Solid color (what you have now) is one paint style, but linear gradient color, radial gradient color, and image paint are others common to path rendering standards. (See the nvpr_svg SDK example to see how simple the shaders are for linear and radial gradients.) * Eventually you could have "paint" shaders where you can use arbitrary assembly, Cg, or GLSL shaders to paint your paths during the cover operation. Environment mapped or bump mapped paths are possibilities. * Have separate fill and stroke paint. Sometimes you want the stroking to happen "before" the filling (such as for matting text rendering) but usually the stroking is an outline around the path drawn over the filled version of the path. Have an option for either. "null" paint would skip the filling or stroking. * Have methods to set stroking styles (end caps, join style, dash pattern, dash caps, and stroke width). * Be able to initialize a path from an actual string of text and a font name (and font style). This way someone can create a osgNVPR::Path for "Hello world" in Arial or whatever. * Have a mode to say whether mixing with depth testing should be done. * Provide an option to "cache" the drawing commands for a path object in a display list. All the NV_path_rendering commands are display-listable. Because the NVIDIA OpenGL driver is dual-core enabled, this allows you to draw a path with a single glCallList command relayed over to the driver thread on another core. This gives your app thread more CPU cycles. * You should be able to support "picking" support with the glIsPointInFillPathNV and glIsPointInStrokePathNV queries. Since you have the bounding box queried already, it makes sense to test against the bounding box first before doing the (more expensive) glIsPointInFillPathNV query. I look forward to seeing how this develops. - Mark ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=42207#42207 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
