This seems like the age-old "you can't draw a flat-shaded cube with 8 vertices" dilemma.
Don't you need to repeat the same xyz vertex possibly multiple times? So that you can have a different normal at the same vertex, depending on which face you're rendering. -Paul On Wed, Jul 23, 2014 at 8:25 AM, Yu Zhang <sciro...@163.com> wrote: > Hi everyone, > > Could anyone share some experience on handle 3D hole drawing? > My implementation seems not good, the details are: > > Suppose a small rect is a hole inside a big rect: > [img]http://www.youpic.tk/view.php?filename=706Hole.png[/img] > > The vertices are 0, 1, 2, 3, 4, 5, 6, 7. I'll do: > 1) for extrusion direction, add some vertices in top plane. vertex 8, 9, > 10, 11, 12, 13, 14, 15. Each vertex is offset from a bottom vertex. eg: 0 > ->8, > 1 -> 9... > 2) Use tessellator to process the bottom plane, get some prim sets with > triangles. > 3) For each triangles in bottom, add a side face prim set from top plane > triangle. eg, for triangle 236, use 10, 11, 14. The side face's triangle > strip is 2, 10, 3, 11, 6, 14, 2, 10. > 4) Add all side faces for each triangles, add bottom, top planes. > > The result looks correct, but it have unnecessary side faces inside model. > It sounds do no harm, but if it enable lighting, the look feel is not good: > [img]http://www.youpic.tk/view.php?filename=474NotgoodLighting.png[/img] > > Turn off lighting seems ok, but it lacks lighting. Maybe this is more like > a modeling question, could you please share your experience, thanks! > Attached the picture also. > > Thank you! > > Cheers, > Yu[/img] > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=60411#60411 > > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > -- -Paul
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