I have a polygon managed by a osg::Geometry object that is interactively modified by the user. Currently, only the point's positions are modified, not the number of points or any other attributes. Each time a point is modified, a call to retessellatePolygon is made on a tessellator object. The same Tessellator object is used multiple times for each modification.
Normally, this appears to work as expected, that is, it tessellates the object. However if I create a quad, and move one corner to the opposite corner, collapsing it into a shape that looks like two lines, the polygon is no longer drawn even after the shape is modified so it's no longer collapsed. If you are using a fixed-point font, the following ASCII diagram shows approximately how the shape is being modified: a b a,d b +---+ +----+ | | --> | +---+ + c d c I get this behavior both with tessellation types TESS_TYPE_GEOMETRY and TESS_TYPE_DRAWABLE. TESS_TYPE_POLYGONS seems to improperly tessellate the polygon after some modification. What I want is for the tessellator to tessellate based on the original geometry plus the modified vertex positions. Looking at how the the osgTessellator example uses the tessellator, I figured the way I was using it would work, but perhaps my mental model of it is flawed. Do I need to recreate the geometry every time before I call retessellate? - Eron _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
