Hi Simeon, I wish that we had this feature too. BUT, examine the following case:
I have a quad geometry, use geometryino and normalgenerator to generate normals, my geometry has hard edges, I retrieve an indexedtrianglearray from the geometryinfo ( can't retrieve an indexedquadarray AFAIK). Now, with this indexedtrianglearray I want to do both outline and surface shading. Would be a problem because my surface is now filled with triangles and not quads. Second Case: I want to let the user color my wireframe geometry to any color of his choice at run time. Don't know if this would be easier to do with textured outlines. I routinely use 2 geometries for the above and some other reasons. Rgds Vaidya >On Thu, 28 Mar 2002 13:18:06 -0600, Simeon H.K. Fitch <[EMAIL PROTECTED]> >wrote: >> -----Original Message----- >> From: Discussion list for Java 3D API >> [mailto:[EMAIL PROTECTED]]On Behalf Of Doug Twilleager >> Sent: Thursday, March 28, 2002 12:50 PM >> To: [EMAIL PROTECTED] >> Subject: Re: [JAVA3D] On-the-fly object editing >> >> >> Their are a few of problems with adding this sort of API. >> First, there is no standard low level support for this sort >> of feature. So, at a minimum, we would simply render the model >> twice with some sort of polygon offset. Calculating the appropriate >> polygon offset is another issue, because it is generally model >> specific. Finally, and most importantly, this feature tends to be >> application specific. The outlines that we would draw, would almost >> never be what you really want. So, it makes sense to leave this in >> application space for now. > >But let's assume that the user provides the polygon offset unit and factor, >and selects PolygonAtributes.POLYGON_FILLED_OUTLINE, it would still be >*much* more beneficial for the renderer to render each polygon twice rather >than require the application to do it. Basically, I'm wondring if Java3D >could do what is shown in the polyoff.c program in the "RedBook": > >... > glEnable(GL_LIGHTING); > glEnable(GL_POLYGON_OFFSET_FILL); > glPolygonOffset(polyfactor, polyunits); > glCallList (list); > glDisable(GL_POLYGON_OFFSET_FILL); > > glDisable(GL_LIGHTING); > glColor3f (lineColorR, lineColorG, lineColorB); > glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); > glCallList (list); > glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); >... > >When you say "there is no standard low level support for this sort of >feature." does that mean that there is no corresponding capability in >DirectX? I could understand that being a feature killer (except for the fact >that things like anti-aliased points and line width are exposed in J3D even >though there isn't DirectX support). > >Also, what do you mean by "outlines that we would draw, would almost never >be what you really want"? Are the properties in LineAttributes not specific >enough to describe what is desired? > >Thanks! > >Simeon Fitch > > ========================================================================== >To unsubscribe, send email to [EMAIL PROTECTED] and include in the body >of the message "signoff JAVA3D-INTEREST". For general help, send email to =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
