Original Post
hello, there is problem with my shadowmap implementation. the areas that are shadowed do not have the correct shadow-color. it seems as if the shadow-color is modulated with the shadow-map itself, since i use multitexturing i have regular textures in GL_TEXTURE0 and the shadow-map in GL_TEXTURE1. and since i must have booth textures active in the 3rd and last pass, it seems that the color of the shadow-map at a certain point is modulated into the normal color. what can i do about this? here is the renderloop [Edited by - ehmdjii on March 2, 2008 5:39:14 AM]
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-10, 10, -10, 10, 0.1, 10.0);
FloatBuffer lpm = FloatBuffer.allocate(16);
glGetFloatv(GL_PROJECTION_MATRIX, lpm);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
new GLU().gluLookAt(2f, 6, 0,
0, 0, 0,
0, 1, 0); // light view matrix
FloatBuffer lvm = FloatBuffer.allocate(16);
glGetFloatv(GL_MODELVIEW_MATRIX, lvm);
glViewport(0, 0, sm_size, sm_size);
glEnable(GL_POLYGON_OFFSET_FILL);
glPolygonOffset(1.1f, 4.0f);
glColorMask(false, false, false, false);
renderScene(gl);
glDisable(GL_POLYGON_OFFSET_FILL);
glActiveTexture(GL_TEXTURE1);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, sm_id.get(0));
glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, sm_size, sm_size);
glColorMask(true, true, true, true);
/**
* 2. pass from camera point of view, without light
*/
glClear(GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
new GLU().gluPerspective(45, 1, 0.1, 1000.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
camera.setOrbit(l, 0.01f, rAngle_roty, rAngle_rotx);
camera.update(null);
glViewport(0,0,width,height);
glColor4f(0.6f,0.6f,0.6f,1f);
renderScene(gl);
/**
* 3. Pass from camera point of view with light
*/
glColor4f(1,1,1,1);
//Calculate texture matrix for projection
//This matrix takes us from eye space to the light's clip space
//It is postmultiplied by the inverse of the current view matrix when specifying texgen
Matrix4f biasMatrix = new Matrix4f( 0.5f, 0.0f, 0.0f, 0.0f,
0.0f, 0.5f, 0.0f, 0.0f,
0.0f, 0.0f, 0.5f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f); //bias from [-1, 1] to [0, 1]
Matrix4f lightprojectionMatrix = Matrix4f.fromFloatBuffer(lpm);
Matrix4f lightviewMatrix = Matrix4f.fromFloatBuffer(lvm);
Matrix4f textureMatrix = biasMatrix.mult(lightprojectionMatrix).mult(lightviewMatrix);
glActiveTexture(GL_TEXTURE1);
glEnable(GL_TEXTURE_2D);
//Set up texture coordinate generation.
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_S, GL_EYE_PLANE, textureMatrix.getRow(0));
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_T, GL_EYE_PLANE, textureMatrix.getRow(1));
glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_R, GL_EYE_PLANE, textureMatrix.getRow(2));
glTexGeni(GL_Q, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_Q, GL_EYE_PLANE, textureMatrix.getRow(3));
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glEnable(GL_TEXTURE_GEN_R);
glEnable(GL_TEXTURE_GEN_Q);
//Bind & enable shadow map texture
glBindTexture(GL_TEXTURE_2D, sm_id.get(0));
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
//Enable shadow comparison
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE_ARB, GL_COMPARE_R_TO_TEXTURE);
//Shadow comparison should be true (ie not in shadow) if r<=texture
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC_ARB, GL_LEQUAL);
//Shadow comparison should generate an INTENSITY result
glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE_ARB, GL_INTENSITY);
renderScene(gl);
//Disable textures and texgen
glActiveTexture(GL_TEXTURE1);
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glDisable(GL_TEXTURE_GEN_R);
glDisable(GL_TEXTURE_GEN_Q);
