Hi Sukender, Do you an online reference to confirm the interpretation of per primitive binding when using triangles and quad strips?
It does sound like your suggestion of adding GL_TRIANGLE_STRIP and FAN to the switch statement setting the primitive length might be appropriate. Could you implement this and test it out? Robert. On Fri, Jan 7, 2011 at 2:16 PM, Sukender <[email protected]> wrote: > Hi again, > About my problem with triangle strips (see below), I found something strange > in Geometry::drawImplementation() : > > unsigned int primLength; > switch(mode) > { > case(GL_POINTS): primLength=1; break; > case(GL_LINES): primLength=2; break; > case(GL_TRIANGLES): primLength=3; break; > case(GL_QUADS): primLength=4; break; > default: primLength=0; break; // compute later when > =0. > } > > // draw primitives by the more flexible "slow" path, > // sending OpenGL glBegin/glVertex.../glEnd(). > switch(primitiveset->getType()) > { > case(PrimitiveSet::DrawArraysPrimitiveType): > { > if (primLength==0) > primLength=primitiveset->getNumIndices(); > > > If i understand well, it means that when having GL_TRIANGLE_STRIP, then > primLength is set to the length of the strip, not the length of a triangle. > Shouldn't the switch statement be extended with other types ? > > case(GL_TRIANGLE_FAN): > case(GL_TRIANGLE_STRIP): > case(GL_TRIANGLES): primLength=3; break; > > Or is 'primLength' used for another purpose ? > Cheers, > > Sukender > PVLE - Lightweight cross-platform game engine - http://pvle.sourceforge.net/ > > ----- "Sukender" <[email protected]> a écrit : > >> Hi Robert & all, >> >> I also got a problem with BIND_PER_PRIMITIVE (yes, I know I should not >> use it! ;) ). When having TRIANGLE_STRIP, with normals per primitive, >> I got one normal per triangle strip, whereas OpenGL seem to say I >> should have one normal per triangle. Am I wrong? >> >> The geometry looks like : >> >> Geometry { >> // blah blah blah... >> PrimitiveSets 3 >> { >> DrawArrays TRIANGLE_STRIP 0 219 >> DrawArrays TRIANGLE_STRIP 219 19 >> DrawArrays TRIANGLE_STRIP 238 15 >> } >> VertexArray Vec3Array 253 >> { >> blah blah blah... >> } >> NormalBinding PER_PRIMITIVE >> NormalArray UniqueID Vec3Array_1 Vec3Array 247 >> { >> 0 0 1 >> 0 1 0 >> 1 0 1 >> ... and all other normals, which are not used at all. >> } >> } >> >> In this case the first "DrawArrays" uses normal 0, the second uses >> normal 1... >> >> I looked into ArrayDispatchers, but I was unable to find something >> usefult to me. >> Help, please? >> Thanks. >> >> Sukender >> PVLE - Lightweight cross-platform game engine - >> http://pvle.sourceforge.net/ >> >> ----- "Robert Osfield" <[email protected]> a écrit : >> >> > Hi Don, >> > >> > On Tue, Sep 21, 2010 at 12:13 AM, Don Leich <[email protected]> wrote: >> > > I confirmed that the bug persists in today's SVN trunk. In the >> > example >> > > already supplied the overall color is not applied when normals are >> > > given as BIND_PER_PRIMITIVE. >> > >> > I've just tested svn/trunk and 2.9.3 and can confirm that there is >> > different behaviour. >> > >> > I've also isolated the two geometries that use BIND_PER_PRIMITIVE >> and >> > they just use this binding for normals, but have no colour array >> > assigned at all. So... they will be inheriting their colour from >> > other geometries in a completely undefined way. >> > >> > This to me doesn't look like a bug at all, but an issue with a >> > under-defined scene graph, and just by luck it's worked before. >> > Please assign colours to all the geometries that need it and then >> > re-test. >> > >> > Robert. >> > _______________________________________________ >> > osg-users mailing list >> > [email protected] >> > >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
