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POOpenGL Shadow Mapping using GLSL
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copied!<p>I am trying to get shadow mapping working using GLSL. Unfortunately my depth render results are unusable even I have a pretty decent depth buffer precision. It is rendering like wireframe, following image may be a better description.</p> <p>I am also including a test case(single file including shader), only dependency is pyopengl. </p> <p><img src="https://i.stack.imgur.com/1ZcNK.png" alt="alt text"></p> <pre><code># shadow mapping test # utkualtinkaya at gmail # shader is from http://www.fabiensanglard.net/shadowmapping/index.php from OpenGL.GL import * from OpenGL.GLU import * from OpenGL.GLUT import * from OpenGL.GL.shaders import * from OpenGL.GL.framebufferobjects import * import math class Camera: def __init__(self): self.rotx, self.roty = math.pi/4, math.pi/4 self.distance = 100 self.moving = False self.ex, self.ey = 0, 0 self.size = (800, 600) def load_matrices(self): glViewport(0, 0, *self.size) y = math.cos(self.roty) * self.distance x = math.sin(self.roty) * math.cos(self.rotx) * self.distance z = math.sin(self.roty) * math.sin(self.rotx) * self.distance glMatrixMode(GL_PROJECTION) glLoadIdentity() gluPerspective(45.0, self.size[0]/float(self.size[1]), 1, 1000) glMatrixMode(GL_MODELVIEW) glLoadIdentity() gluLookAt(x,y,z, 0,0,0, 0,1,0) def on_mouse_button (self, b, s, x, y): self.moving = not s self.ex, self.ey = x, y if b in [3, 4]: dz = (1 if b == 3 else -1) self.distance += self.distance/15.0 * dz; def on_mouse_move(self, x, y, z = 0): if self.moving: self.rotx += (x-self.ex) / 300.0 self.roty += -(y-self.ey) / 300.0 self.ex, self.ey = x, y def set_size(self, w, h): self.size = w, h class Shader(): def __init__(self): self.is_built = False self.uniforms = {} def build(self): self.program = compileProgram( compileShader(''' uniform mat4 camMatrix; uniform mat4 shadowMatrix; varying vec4 depthProjection; uniform bool useShadow; void main() { gl_Position = camMatrix * gl_ModelViewMatrix * gl_Vertex; depthProjection = shadowMatrix * gl_ModelViewMatrix * gl_Vertex; gl_FrontColor = gl_Color; } ''',GL_VERTEX_SHADER), compileShader(''' varying vec4 depthProjection; uniform sampler2D shadowMap; uniform bool useShadow; void main () { float shadow = 1.0; if (useShadow) { vec4 shadowCoord = depthProjection / depthProjection.w ; // shadowCoord.z -= 0.0003; float distanceFromLight = texture2D(shadowMap, shadowCoord.st).z; if (depthProjection .w > 0.0) shadow = distanceFromLight < shadowCoord.z ? 0.5 : 1.0 ; } gl_FragColor = shadow * gl_Color; } ''',GL_FRAGMENT_SHADER),) self.is_built = True self.uniforms['camMatrix'] = glGetUniformLocation(self.program, 'camMatrix') self.uniforms['shadowMatrix'] = glGetUniformLocation(self.program, 'shadowMatrix') self.uniforms['shadowMap'] = glGetUniformLocation(self.program, 'shadowMap') self.uniforms['useShadow'] = glGetUniformLocation(self.program, 'useShadow') print self.uniforms def use(self): if not self.is_built: self.build() glUseProgram(self.program) class Test: def __init__(self): glutInit(sys.argv) glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH) glutInitWindowSize(800, 600) glutInitWindowPosition(1120/2, 100) self.window = glutCreateWindow("Shadow Test") self.cam = Camera() self.light = Camera() self.cam.set_size(800, 600) self.light.set_size(2048, 2048) self.light.distance = 100 self.shader = Shader() self.initialized = False def setup(self): self.initialized = True glClearColor(0,0,0,1.0); glDepthFunc(GL_LESS) glEnable(GL_DEPTH_TEST) self.fbo = glGenFramebuffers(1); self.shadowTexture = glGenTextures(1) glBindFramebuffer(GL_FRAMEBUFFER, self.fbo) w, h = self.light.size glActiveTexture(GL_TEXTURE5) glBindTexture(GL_TEXTURE_2D, self.shadowTexture) glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP ); glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP ); glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, w, h, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, None) glDrawBuffer(GL_NONE) glReadBuffer(GL_NONE) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, self.fbo, 0) FBOstatus = glCheckFramebufferStatus(GL_FRAMEBUFFER) if FBOstatus != GL_FRAMEBUFFER_COMPLETE: print ("GL_FRAMEBUFFER_COMPLETE_EXT failed, CANNOT use FBO\n"); glBindFramebuffer(GL_FRAMEBUFFER, 0) #glActiveTexture(GL_TEXTURE0) def draw(self): glPushMatrix() glTranslate(0, 10 ,0) glColor4f(0, 1, 1, 1) glutSolidCube(5) glPopMatrix() glPushMatrix() glColor4f(0.5, 0.5, .5, 1) glScale(100, 1, 100) glutSolidCube(1) glPopMatrix() def apply_camera(self, cam): cam.load_matrices() model_view = glGetDoublev(GL_MODELVIEW_MATRIX); projection = glGetDoublev(GL_PROJECTION_MATRIX); glMatrixMode(GL_MODELVIEW) glLoadIdentity() glMultMatrixd(projection) glMultMatrixd(model_view) glUniformMatrix4fv(self.shader.uniforms['camMatrix'], 1, False, glGetFloatv(GL_MODELVIEW_MATRIX)) glLoadIdentity() def shadow_pass(self): glUniform1i(self.shader.uniforms['useShadow'], 0) glBindFramebuffer(GL_FRAMEBUFFER, self.fbo) glClear(GL_DEPTH_BUFFER_BIT) glCullFace(GL_FRONT) self.apply_camera(self.light) self.draw() glBindFramebuffer(GL_FRAMEBUFFER, 0) def final_pass(self): glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) self.light.load_matrices() model_view = glGetDoublev(GL_MODELVIEW_MATRIX); projection = glGetDoublev(GL_PROJECTION_MATRIX); glMatrixMode(GL_MODELVIEW) glLoadIdentity() bias = [ 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] glLoadMatrixd(bias) glMultMatrixd(projection) glMultMatrixd(model_view) glUniformMatrix4fv(self.shader.uniforms['shadowMatrix'], 1, False, glGetFloatv(GL_MODELVIEW_MATRIX)) glActiveTexture(GL_TEXTURE5) glBindTexture(GL_TEXTURE_2D, self.shadowTexture) glUniform1i(self.shader.uniforms['shadowMap'], 5) glUniform1i(self.shader.uniforms['useShadow'], 1); self.apply_camera(self.cam) glLoadIdentity() glCullFace(GL_BACK) self.draw() def render(self): if not self.initialized: self.setup() self.shader.use() self.shadow_pass() self.final_pass() glutSwapBuffers() def mouse_move(self, *args): self.cam.on_mouse_move(*args) self.light.on_mouse_move(*args) def mouse_button(self, b, *args): if b==0: self.light.on_mouse_button(b, *args) else: self.cam.on_mouse_button(b, *args) def main(self): glutDisplayFunc(self.render) glutIdleFunc(self.render) glutMouseFunc(self.mouse_button) glutMotionFunc(self.mouse_move) glutReshapeFunc(self.cam.set_size) #self.setup() glutMainLoop() if __name__ == '__main__': test = Test() test.main() </code></pre>

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