Hello,
I'm trying to get GLSL shadowmapping working. I've made functions so that they wouldn't clutter the main. I believe the problem is in the texture matrix projecting. Here's the draw part of the main:
glLibUseShader(BlankShader)
#Clears color/depth buffers, resets matrix
Window.clear()
#Set the view from the light's point of view.
LightView.set_view()
gluLookAt(0,100,0,
0,0,-4,
0.0,1.0,0.0)
#Self-explanatory
DrawTeapot()
DrawFloor()
#Not quite sure if this is right. I'll provide function later.
projmat = glLibShadowGetProjMat([0,100,0],[0,0,-4],5,96,102)
#Render scene to a depth texture. I've tested this, and I'm sure it works.
depthmap = glLibSceneToDepthMap(512,depthmap)
#Clear window again
Window.clear()
#Set the camera's view (no call to gluLookAt() because camera at origin).
View3D.set_view()
glLightfv(GL_LIGHT0,GL_POSITION,[0,100,0,1.0])
glLibUseShader(ShadowShader)
ShadowShader.pass_shadow_texture(depthmap)
#Not entirely sure about these either.
glMatrixMode(GL_TEXTURE)
glLoadMatrixf(projmat)
DrawTeapot()
DrawFloor()
Here's where the texture matrix is projected:
def glLibShadowGetProjMat(lightpos,center,angle,near,far):
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(angle,1.0,near,far)
LightProjectionMatrix = glGetFloatv(GL_PROJECTION_MATRIX)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
gluLookAt(lightpos[0],lightpos[1],lightpos[2],
center[0],center[1],center[2],
0.0,1.0,0.0)
LightViewMatrix = glGetFloatv(GL_MODELVIEW_MATRIX)
glMatrixMode(GL_TEXTURE)
glPushMatrix()
glLoadMatrixf([[0.5,0.0,0.0,0.0],
[0.0,0.5,0.0,0.0],
[0.0,0.0,0.5,0.0],
[0.5,0.5,0.5,1.0]])
glMultMatrixf(LightProjectionMatrix)
glMultMatrixf(LightViewMatrix)
TextureMatrix = glGetFloatv(GL_TEXTURE_MATRIX)
glPopMatrix()
return TextureMatrix
Finally, the relevant parts of the shaders:
//RELEVANT VERTEX SHADER SECTION
ProjCoord = gl_TextureMatrix[0]*(gl_ModelViewMatrix*gl_Vertex);
//ProjCoord is then sent to the fragment shader.
//RELEVANT FRAGMENT SHADER SECTION
//color created, set by a phong lighting model here
float rValue = shadow2DProj(shadtex1,ProjCoord).r + 0.3;
rValue = clamp(rValue, 0.0, 1.0);
vec3 CoordPos = ProjCoord.xyz / ProjCoord.w;
if(CoordPos.x>=0.0 && CoordPos.y>=0.0 && CoordPos.x<=1.0 && CoordPos.y<=1.0) {
color *= rValue;
}
All this doesn't work, though. Strangely, I don't see the teapot object at all (should be about mid-screen here). I do however see the floor (gold on the bottom), which isn't entirely blank. I see a ghost image of the teapot on it, which looks like someone took the depth texture, and combined it with the floor material:
Please help me fix this! Thanks,
Geometrian
