I am trying to implement shadow mapping in our game project. I am using the render method for a texture with two pass rendering. First I created a FBO and linked the texture for the depth component only. In the first pass, I turn on this FBO, turn off the texture and visualize my scene from the light POV. In the second pass, I pass the depth texture to the shader and render the scene normally. I am doing shadow related calculations in a shader.
But my code does not work correctly. I do not see the shadow. In addition, when I look through both passages, I see how a multiple drawing of the whole world freezes one after the other, if the camera looks above a certain angle: 45. If I look below this angle, the rendering looks normal. What could be the source of this problem? If I turn off the first pass, the world will look darker, but the final scene will disappear. I also added my codes below.
I also have another confusion. I have disabled the texture for the first pass shadowmap. But I am sending texture coordinates with vertex coordinates in VBO. Will this cause any problems?
FBO Initialization
LightPosition = glm::vec3(50.0f, 40.0f, 50.0f); upVector = glm::vec3(0.0f, 1.0f, 0.0f); glGenTextures(1, &m_shadowMap); glBindTexture(GL_TEXTURE_2D, m_shadowMap); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL); glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_INTENSITY); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32, WindowWidth, WindowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL); glBindTexture(GL_TEXTURE_2D, 0); glGenFramebuffers(1, &m_fbo); glBindFramebuffer(GL_FRAMEBUFFER, m_fbo); glDrawBuffers(0, NULL); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, m_shadowMap, 0); glBindFramebuffer(GL_FRAMEBUFFER, 0); glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); GLenum Status = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (Status != GL_FRAMEBUFFER_COMPLETE) { printf("FB error, status: 0x%x\n", Status); return false; } return true;
Passage of the shadow map:
glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, 0); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, 0); glViewport(0, 0, windowWidth, windowHeight); glBindFramebuffer(GL_FRAMEBUFFER, shadowMapFBO.m_fbo); glClear(GL_DEPTH_BUFFER_BIT); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glm::mat4 lightProjection = glm::perspective(45.0f, 1.0f * windowWidth / windowHeight, 0.125f, 1000.0f); glGetFloatv(GL_PROJECTION_MATRIX, shadowMapFBO.LightProjectionMatrix); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glm::mat4 lightModelView = glm::lookAt(shadowMapFBO.LightPosition, glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f)); glGetFloatv(GL_MODELVIEW_MATRIX, shadowMapFBO.LightModelViewMatrix); glm::mat4 lmvp = lightProjection * lightModelView; glCullFace(GL_FRONT); glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); glDisable(GL_LIGHTING); glDisable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, 0); glUniform1i(Shader::id_uniform_layer, 0); world->render(lmvp); printGLError(); glBindFramebuffer(GL_FRAMEBUFFER, 0);
Render pass:
static glm::vec3 cCameraPosition = glm::vec3(0.0f, 5.0f, 10.0f); static glm::vec3 cLightPosition = glm::vec3(50.0f, 40.0f, 50.0f); glBindFramebuffer(GL_FRAMEBUFFER, 0); glViewport(0, 0, windowWidth, windowHeight); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glm::mat4 modelView = player->getView(); float viewAngle = 45.0f; glMatrixMode(GL_PROJECTION); glLoadIdentity(); glm::mat4 projection = glm::perspective(viewAngle, 1.0f * windowWidth / windowHeight, 0.01f, 1000.0f); glm::mat4 mvp = projection * modelView; glEnable(GL_TEXTURE_2D); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, shadowMapFBO.m_shadowMap); glMatrixMode(GL_TEXTURE); glLoadIdentity(); glTranslatef(0.5f, 0.5f, 0.5f); glScalef(0.5f, 0.5f, 0.5f); glMultMatrixf(shadowMapFBO.LightProjectionMatrix); glMultMatrixf(shadowMapFBO.LightModelViewMatrix); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, id_texture_blocks); glUseProgram(Shader::id_program); glUniform3fv(Shader::id_uniform_lightPosition, 1, glm::value_ptr(cLightPosition)); glUniform3fv(Shader::id_uniform_CameraPosition, 1, glm::value_ptr(*(player->getCoordinates())));
Vertex Shader:
attribute vec4 coordinates; uniform mat4 mvp; //Fragment shader forward variables. varying vec4 voxel; //shadow map // Used for shadow lookup varying vec4 ShadowCoord; uniform vec3 LightPosition, CameraPosition; varying vec3 LightDirection, LightDirectionReflected, CameraDirection, Normal; void main(void) { //shadow map LightDirection = LightPosition - gl_Vertex.xyz; LightDirectionReflected = reflect(-LightDirection, gl_Normal); CameraDirection = CameraPosition - gl_Vertex.xyz; Normal = gl_Normal; gl_TexCoord[0] = gl_MultiTexCoord0; gl_TexCoord[1] = gl_TextureMatrix[1] * gl_Vertex; voxel = coordinates; //Calculates projection on xyz. gl_Position = mvp * vec4(coordinates.xyz, 1); }
Fragment Shader:
#extension GL_EXT_gpu_shader4 : enable //Rendering layer. uniform int layer; //Colors. uniform float colorRed; uniform float colorGreen; uniform float colorBlue; uniform float colorAlpha; //Fog density. uniform float fogDensity; varying vec4 voxel; uniform sampler2D texture; const float N_TEXTURES = 32.0; //////////////////////shadow map uniform sampler2DShadow ShadowMap; varying vec4 ShadowCoord; varying vec3 LightDirection, LightDirectionReflected, CameraDirection, Normal; void main(void) { vec2 coord2d; float intensity; vec4 color = texture2D(texture, coord2d); float z = gl_FragCoord.z / gl_FragCoord.w; float fog = clamp(exp(-fogDensity * z * z), 0.2, 1.0); color.xyz = color.xyz * intensity; //shadow map float Shadow = shadow2DProj(ShadowMap, gl_TexCoord[1]).r; float NdotLD = max(dot(normalize(LightDirection), Normal), 0.0) * Shadow; float Spec = pow(max(dot(normalize(LightDirectionReflected), normalize(CameraDirection)), 0.0), 32.0) * Shadow; color.xyz = color.xyz * (0.25 + NdotLD * 0.75 + Spec); //Final color. vec4 fogColor = vec4(colorRed, colorGreen, colorBlue, colorAlpha); gl_FragColor = mix(fogColor, color, fog); }