[osg-users] ShadowMap problem...

Wyatt Earp wyattbsearp1881 at gmail.com
Thu Nov 12 10:54:10 PST 2009


I think I am about to get this straightened out...

I have implemented the LiSPPSM shadow code in my app.  My scene consists of
two vehicles and a terrain.  If I don't add the terrain, I can see the
shadows on the base test geometry and it looks pretty good.  The base
geometry just happens to be sitting below my two vehicles.  If I do add the
terrain, most of the terrain is covered by a big black square, and I no
longer see the shadows on the base geometry (I can descend below the
geometry of the terrain and see the base geometry).  Is something possibly
casting a large shadow on the terrain to cause the big black square?  I am
not sure what it could be since I only have the terrain, two vehicles and
the base geometry.  Any suggestions?

Thx
W



> -----Original Message-----
> From: osg-users-bounces at lists.openscenegraph.org [mailto:osg-users-
> bounces at lists.openscenegraph.org] On Behalf Of Jean-Sébastien Guay
> Sent: Wednesday, November 11, 2009 2:33 PM
> To: OpenSceneGraph Users
> Subject: Re: [osg-users] ShadowMap problem...
> 
> Hi Wyatt,
> 
> > With the debugHUD in the ShadowMap example, there was just
> > a window which appeared to display the shadow map in gray-scale, but
> in the
> > LISPSM example, there appears to be two sub-windows in the debughud
> window
> > (not in gray-scale). What are these displaying?
> 
> The left side is the shadow map itself, and the right side is a render
> of the bounds analysis render pass (the
> LightSpacePerspectiveShadowMapDB
> technique - Draw Bounds - makes a 64x64 render pass before the actual
> shadow pass to see if the shadow map bounds can be further reduced -
> Wojtek can tell you more about it, or search the archives for details).
> 
> > Am I supposed to, basically, copy the shader code from StandardShader
> map
> > and add it to my shaders and turn off the LISPSM shaders?
> 
> You only need to use some parts, those that relate to the shadow test.
> The rest of your shader can be what you want - most of the shader code
> in StandardShadowMap.cpp is just standard lighting, which you might be
> doing differently. You should copy the DynamicShadow function for both
> vertex and fragment shader (whether you want to keep it in a function
> or
> not, up to you) and then look at the place where it's used and do
> something similar.
> 
> Read the shaders, you should understand.
> 
> J-S
> --
> ______________________________________________________
> Jean-Sebastien Guay    jean-sebastien.guay at cm-labs.com
>                                 http://www.cm-labs.com/
>                          http://whitestar02.webhop.org/
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