Anybody have any parallax bump mapping examples for OSG? This sort of algorithm may work for plowing: http://www.simcreator.com/clips/deformable_snow.wmv
Zach -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Speed Sent: Monday, April 16, 2007 22:23 To: osg users Subject: Re: [osg-users] Snow plowing I'm certainly no expert, but it seems to me that if you are clever you might be able to use the bump-mapping texture at one level for the vertex deformation (in the fragment shader) at the higher level of detail. Generally, bump-mapping uses a normal map from a texture. I don't know what the performance impact would be calculating the normals on the fly (in GLSL) from height displacement. Seems similar in many ways to parallax bump-mapping. -Paul Zach Deedler wrote: > Hi Robert, > > I thought about the height field for plowing. The only problem I see > there is rendering large areas. This would result in a lot of > vertices which would render horribly. This calls for > levels-of-detail, which will complicate things greatly. Do we just > add lower-levels of detail, and modify all LODs when plowing? > > Also, I am concerned that a height field will result in blocky looking > snow clearing. > > What about bump maps? > > > Zach > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Robert > Osfield > Sent: Monday, April 16, 2007 14:36 > To: osg users > Subject: Re: [osg-users] Snow plowing > > Hi Zach, > > On 4/16/07, Zach Deedler <[EMAIL PROTECTED]> wrote: >> INVESTIGATION >> I1) I am investigating moving/removing/adding vertices in real-time. >> I2) I am also investigating modifying texture alpha values (Kind of >> like erasing the overlying snow). >> >> QUESTIONS >> Q1) Are there any osg examples that may help me in this investigation? >> Examples that may dynamically move/remove/add vertices in real-time? > > The osgTDS does adding of vertices on loadtime, not quite real-time > but it might give you something to review. > > There arn't any other OSG examples don't do adding/removing vertices. > In general I'd say try to avoid adding and removing vertices, by > adjusting their heights/colours. If keep a static mesh with static > base attributes, and minimize the amount of data you update per frame > then you should be in a good position for hitting real-time needs. > >> Q2) I am looking for consultation for simulating snow plowing with >> OSG. If anybody believes they have the expertise to do this please > contact me. > > I'm not available right now alas, it'd would be a fun project though > :-) > >> Q3) Anybody have suggestions on how to implement snow plowing? > > I'd try out using a static height field that is displaced by values > that are updated in real-time, a simple vertex shader could do the > displacement either reading the z values for float tex coord array, or > from using tex read. > > It just so happens that some of the upcoming work on osgTerrain will > provide support for doing displacement maps that can be updated in real-time. > Perhaps this could be reused for your purpose. > > Robert. > _______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users > http://www.openscenegraph.org/ > > _______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users > http://www.openscenegraph.org/ _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/ _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
