Hi, Various thoughts:
What graphics card? Not all support vertex textures in hardware, and may have different capabilities when they do. Check the InfoLog outputs from the compile and link, they may provide hints (ATI says when the shader forced a slow path.) FYI texture2DLod is only necessary when using a mipmapped texture. Are you? That could also have a performance impact. cheers -- mew Zach Deedler wrote: > Hi Paul, > > Yes I could've been more descriptive. "renders horribly", like 1fps. The > texture I'm using is 512x256. The draw time is 1128ms. I'm up to date with > my drivers. > > Zach > > > >>-----Original Message----- >>From: [EMAIL PROTECTED] >>[mailto:[EMAIL PROTECTED] On Behalf Of Paul Speed >>Sent: Sunday, April 29, 2007 21:29 >>To: osg users >>Subject: Re: [osg-users] Height map vertex shader >> >>Can you describe what you mean by "renders horribly"? >>Perhaps that will provide a clue. >> >>Is this just a flat shaded shape? I noticed you aren't >>giving it texture or color or anything. >> >>-Paul >> >>Zach Deedler wrote: >> >>>Hello osg-users, >>> >>>I'm trying to implement dynamic terrain displacement using >> >>a shader. >> >>>I am trying to just edit a texture to cause the vertex >> >>shader to look >> >>>at the texture, and modify the vertex displacement. But, when I >>>implemented it, it renders horribly. Anybody see what I >> >>did wrong in my vertex shader? >> >>>uniform sampler2D heightMapSampler; >>>void main() >>>{ >>> vec3 vertex; >>> >>> gl_TexCoord[0] = gl_MultiTexCoord0; >>> vec4 heightMap = texture2D( heightMapSampler, >> >>gl_MultiTexCoord0.st ); >> >>> vertex.xy = gl_Vertex.xy; >>> //Add displacement to vertex. >>> vertex.z = gl_Vertex.z + heightMap.r; >>> gl_Position = gl_ModelViewProjectionMatrix * vec4(vertex,1.0); } >>> >>>I have a feeling I'm supposed to be using texture2DLod in >> >>the vertex >> >>>shader, or that this just isn't a viable way to do vertex >> >>displacements. >> >>>Thanks. -- Mike Weiblen -- Austin Texas USA -- http://mew.cx/ _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
