I'm doing Dual depth peeling. I want to ask you, how to properly. I have algorithm like this.
glDisable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBindFramebuffer(GL_FRAMEBUFFER, dualDepthFBOID);
// Render targets 1 and 2 store the front and back colors
// Clear to 0.0 and use MAX blending to filter written color
// At most one front color and one back color can be written every pass
glDrawBuffers(2, &drawBuffers[1]);
glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
GL_CHECK_ERRORS
// Render target 0 stores (-minDepth, maxDepth, alphaMultiplier)
glDrawBuffer(drawBuffers[0]);
glClearColor(-MAX_DEPTH, -MAX_DEPTH, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
glBlendEquation(GL_MAX);
DrawScene(MVP, initShader);
// 2. Depth peeling + blending pass
glDrawBuffer(drawBuffers[6]);
glClearColor(bg.x, bg.y, bg.z, bg.w);
glClear(GL_COLOR_BUFFER_BIT);
int numLayers = (NUM_PASSES - 1) * 2;
int currId = 0;
for (int layer = 1; bUseOQ || layer < numLayers; layer++) {
currId = layer % 2;
int prevId = 1 - currId;
int bufId = currId * 3;
glDrawBuffers(2, &drawBuffers[bufId+1]);
glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
glDrawBuffer(drawBuffers[bufId+0]);
glClearColor(-MAX_DEPTH, -MAX_DEPTH, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
// Render target 0: RG32F MAX blending
// Render target 1: RGBA MAX blending
// Render target 2: RGBA MAX blending
glDrawBuffers(3, &drawBuffers[bufId+0]);
glBlendEquation(GL_MAX);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_RECTANGLE, depthTexID[prevId]);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_RECTANGLE, texID[prevId]);
DrawScene(MVP, dualPeelShader, true,true);
// Full screen pass to alpha-blend the back color
glDrawBuffer(drawBuffers[6]);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
if (bUseOQ) {
glBeginQuery(GL_SAMPLES_PASSED_ARB, queryId);
}
GL_CHECK_ERRORS
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_RECTANGLE, backTexID[currId]);
blendShader.Use();
DrawFullScreenQuad();
blendShader.UnUse();
if (bUseOQ) {
glEndQuery(GL_SAMPLES_PASSED);
GLuint sample_count;
glGetQueryObjectuiv(queryId, GL_QUERY_RESULT, &sample_count);
if (sample_count == 0) {
break;
}
}
GL_CHECK_ERRORS
}
GL_CHECK_ERRORS
glDisable(GL_BLEND);
// 3. Final render pass
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDrawBuffer(GL_BACK_LEFT);
glBindTexture(GL_TEXTURE_RECTANGLE, colorBlenderTexID);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_RECTANGLE, depthTexID[currId]);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_RECTANGLE, texID[currId]);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_RECTANGLE, colorBlenderTexID);
finalShader.Use();
DrawFullScreenQuad();
finalShader.UnUse();
I'm doing lighting in dualPeelShader, where are lighting each pass. This is resulting to extremly bright object. Should I do lighting in finalShader?
---EDIT----
Peel Fragment Shader
#version 330 core
layout(location = 0) out vec4 vFragColor0;
layout(location = 1) out vec4 vFragColor1;
layout(location = 2) out vec4 vFragColor2;
uniform vec4 vColor;
uniform float isObject;
uniform vec3 LightPosition;
uniform sampler2DRect depthBlenderTex;
uniform sampler2DRect frontBlenderTex;
in vec4 vOutColor;
in vec3 position;
in vec3 normal;
in vec3 eyeDirection;
in vec3 lightDirection;
#define MAX_DEPTH 1.0
vec4 Lighted()
{
vec3 LightColor = vec3(1.0,1.0,1.0);
float LightPower = 50;
// Material properties
vec3 MaterialDiffuseColor = vOutColor.rgb;
vec3 MaterialAmbientColor = vec3(0.1,0.1,0.1) * MaterialDiffuseColor;
vec3 MaterialSpecularColor = vec3(0.3,0.3,0.3);
// Distance to the light
float distance = length( LightPosition - position );
// Normal of the computed fragment, in camera space
vec3 n = normalize( normal );
// Direction of the light (from the fragment to the light)
vec3 l = normalize( lightDirection);
// Cosvaryinge of the angle between the normal and the light direction,
// clamped above 0
// - light is at the vertical of the triangle -> 1
// - light is perpendicular to the triangle -> 0
// - light is behvaryingd the triangle -> 0
float cosTheta = clamp( dot( n,l ), 0,1 );
// Eye vector (towards the camera)
vec3 E = normalize(eyeDirection);
// Direction in which the triangle reflects the light
vec3 R = reflect(-l,n);
// Cosvaryinge of the angle between the Eye vector and the Reflect vector,
// clamped to 0
// - Lookvaryingg varyingto the reflection -> 1
// - Lookvaryingg elsewhere -> < 1
float cosAlpha = clamp( dot( E,R ), 0,1 );
return vec4(MaterialAmbientColor + MaterialDiffuseColor * LightColor * LightPower * cosTheta / (distance*distance) +
MaterialSpecularColor * LightColor * LightPower * pow(cosAlpha,5) / (distance*distance),vOutColor.a);
}
void main(void)
{
float fragDepth = gl_FragCoord.z;
vec2 depthBlender = texture(depthBlenderTex, gl_FragCoord.xy).xy;
vec4 forwardTemp = texture(frontBlenderTex, gl_FragCoord.xy);
// Depths and 1.0-alphaMult always increase
// so we can use pass-through by default with MAX blending
vFragColor0.xy = depthBlender;
// Front colors always increase (DST += SRC*ALPHA_MULT)
// so we can use pass-through by default with MAX blending
vFragColor1 = forwardTemp;
// Because over blending makes color increase or decrease,
// we cannot pass-through by default.
// Each pass, only one fragment writes a color greater than 0
vFragColor2 = vec4(0.0);
float nearestDepth = -depthBlender.x;
float farthestDepth = depthBlender.y;
float alphaMultiplier = 1.0 - forwardTemp.w;
if (fragDepth < nearestDepth || fragDepth > farthestDepth) {
// Skip this depth in the peeling algorithm
vFragColor0.xy = vec2(-MAX_DEPTH);
return;
}
if (fragDepth > nearestDepth && fragDepth < farthestDepth) {
// This fragment needs to be peeled again
vFragColor0.xy = vec2(-fragDepth, fragDepth);
return;
}
// If we made it here, this fragment is on the peeled layer from last pass
// therefore, we need to shade it, and make sure it is not peeled any farther
vFragColor0.xy = vec2(-MAX_DEPTH);
vec4 Color;
if(isObject == 0.0)
Color = vColor;
else
Color = Lighted();
if (fragDepth == nearestDepth) {
vFragColor1.xyz += Color.rgb * Color.a * alphaMultiplier;
vFragColor1.w = 1.0 - alphaMultiplier * (1.0 - Color.a);
} else {
vFragColor2 += Color;
}
}
Blend Fragment Shader
#version 330 core
uniform sampler2DRect tempTexture;
layout(location = 0) out vec4 vFragColor;
void main(void)
{
vFragColor = texture(tempTexture, gl_FragCoord.xy);
if(vFragColor.a == 0)
discard;
}
Related
Following the learnopengl tutorial (https://learnopengl.com/Advanced-Lighting/Deferred-Shading)
the author leaves fixed the amount of light (32 lights) as shown by the GLSL:
#version 330 core
out vec4 FragColor;
in vec2 TexCoords;
uniform sampler2D gPosition;
uniform sampler2D gNormal;
uniform sampler2D gAlbedoSpec;
struct Light {
vec3 Position;
color;
};
const int NR_LIGHTS = 32;
uniform Light lights [NR_LIGHTS];
uniform vec3 viewPos;
void main ()
{
// retrieve data from G-buffer
vec3 FragPos = texture (gPosition, TexCoords) .rgb;
vec3 Normal = texture (gNormal, TexCoords) .rgb;
vec3 Albedo = texture (gAlbedoSpec, TexCoords) .rgb;
float Specular = texture (gAlbedoSpec, TexCoords) .a;
// then calculate lighting as usual
vec3 lighting = Albedo * 0.1; // hard-coded ambient component
vec3 viewDir = normalize (viewPos - FragPos);
for (int i = 0; i <NR_LIGHTS; ++ i)
{
// diffuse
vec3 lightDir = normalize (lights [i] .Position - FragPos);
vec3 diffuse = max (dot (Normal, lightDir), 0.0) * Albedo * lights [i] .Color;
lighting + = diffuse;
}
FragColor = vec4 (lighting, 1.0);
}
And when it comes to applying the lights:
glBindFramebuffer (GL_FRAMEBUFFER, 0);
// 2. lighting pass: calculate lighting by iterating over screen filled quad pixel-by-pixel using the gbuffer's content.
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shaderLightingPass.use ();
glActiveTexture (GL_TEXTURE0);
glBindTexture (GL_TEXTURE_2D, gPosition);
glActiveTexture (GL_TEXTURE1);
glBindTexture (GL_TEXTURE_2D, gNormal);
glActiveTexture (GL_TEXTURE2);
glBindTexture (GL_TEXTURE_2D, gAlbedoSpec);
// send light relevant uniforms
for (unsigned int i = 0; i <lightPositions.size (); i ++)
{
shaderLightingPass.setVec3 ("lights [" + std :: to_string (i) + "] .Position", lightPositions [i]);
shaderLightingPass.setVec3 ("lights [" + std :: to_string (i) + "] .Color", lightColors [i]);
// update attenuation parameters and calculate radius
const float constant = 1.0; // note that we do not send this to the shader, we assume it is always 1.0 (in our case)
const float linear = 0.7;
const float quadratic = 1.8;
shaderLightingPass.setFloat ("lights [" + std :: to_string (i) + "] .Linear", linear);
shaderLightingPass.setFloat ("lights [" + std :: to_string (i) + "] .Quadratic", quadratic);
}
shaderLightingPass.setVec3 ("viewPos", camera.Position);
// finally render quad
renderQuad ();
but I would like to be able to add as many lights as I want, because my project will have countless lights (laser guns, bonfire, blast), so I made some changes:
GLSL:
uniform Light light;
uniform vec3 viewPos;
void main()
{
// retrieve data from gbuffer
vec3 FragPos = texture(gPosition, TexCoords).rgb;
vec3 Normal = texture(gNormal, TexCoords).rgb;
vec3 Diffuse = texture(gAlbedoSpec, TexCoords).rgb;
float Specular = texture(gAlbedoSpec, TexCoords).a;
// then calculate lighting as usual
vec3 lighting = Diffuse * 0.1; // hard-coded ambient component
vec3 viewDir = normalize(viewPos - FragPos);
// diffuse
vec3 lightDir = normalize(light.Position - FragPos);
vec3 diffuse = max(dot(Normal, lightDir), 0.0) * Diffuse * light.Color;
// specular
vec3 halfwayDir = normalize(lightDir + viewDir);
float spec = pow(max(dot(Normal, halfwayDir), 0.0), 16.0);
vec3 specular = light.Color * spec * Specular;
// attenuation
float distance = length(light.Position - FragPos);
float attenuation = 1.0 / (1.0 + light.Linear * distance + light.Quadratic * distance * distance);
diffuse *= attenuation;
specular *= attenuation;
lighting += diffuse + specular;
FragColor = vec4(lighting, 1.0);
}
And then I passed the values one by one and rendered a quad:
for (unsigned int i = 0; i < lightPositions.size(); i++)
{
shaderLightingPass.use();
shaderLightingPass.setInt("gPosition", 0);
shaderLightingPass.setInt("gNormal", 1);
shaderLightingPass.setInt("gAlbedoSpec", 2);
shaderLightingPass.setVec3("light.Position", lightPositions[i]);
shaderLightingPass.setVec3("light.Color", lightColors[i]);
const float constant = 1.0; // note that we don't send this to the shader, we assume it is always 1.0 (in our case)
const float linear = 0.7;
const float quadratic = 0.08;
shaderLightingPass.setFloat("light.Linear", linear);
shaderLightingPass.setFloat("light.Quadratic", quadratic);
shaderLightingPass.setVec3("viewPos", camera.Position);
renderQuad();
glUseProgram(-1);
}
and also added a new shader to render the framebuffer on the screen:
screenShader.use();
renderQuad();
but my code renders only the first light:
Result
could anyone tell me what I am doing wrong and how to add the lights in the end result?
Please include code like below
void renderDeferredPass(int i)
{
glUseProgram(ps[Passes::Deferred]);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, g_fbo);
glDepthMask(GL_TRUE);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glDisable(GL_BLEND);
//mat4 model = glm::scale(mat4(1.0f), vec3(3.1f, 3.1f, 3.1f));
model = glm::translate(mat4(1.0f), vec3(-150.0f, -600.0f, -800.0f+camera));
model = glm::rotate(model, 30.0f, vec3(0.0f, 1.0f, 0.0f));
mat4 view = glm::lookAt(glm::vec3(0.0, 0.0, 0.0), glm::vec3(0.0, 0.0, -5.0), glm::vec3(0.0, 1.0, 0.0));
glUniformMatrix4fv(modelLocation, 1, GL_FALSE, &model[0][0]);
glUniformMatrix4fv(viewLocation, 1, GL_FALSE, &view[0][0]);
glUniformMatrix4fv(projLocation, 1, GL_FALSE, &projection[0][0]);
glUniform1i(textureLocation, 0);
quad->Render();
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glUseProgram(0);
glDepthMask(GL_FALSE);
glDisable(GL_DEPTH_TEST);
}
And
void renderLightPass()
{
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glClear(GL_COLOR_BUFFER_BIT);
glEnable(GL_BLEND);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_ONE, GL_ONE);
glUseProgram(ps[Passes::LightPass]);
glBindVertexArray(quadVAO);
bindUbo();
for (unsigned int i = 0; i < NUM_GBUFFER_TEXTURES; i++)
{
glActiveTexture(GL_TEXTURE1 + i);
glBindTexture(GL_TEXTURE_2D,
g_textures[POSITION_TEXTURE + i]);
}
glUniform1i(mapLocations[POSITION_TEXTURE], 1);
glUniform1i(mapLocations[DIFFUSE_TEXTURE], 2);
glUniform1i(mapLocations[NORMAL_TEXTURE], 3);
glUniform1i(mapLocations[TEXCOORD_TEXTURE], 4);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, 0);
glUseProgram(0);
glBindVertexArray(0);
glEnable(GL_DEPTH_TEST);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
And your draw function should look like
void display()
{
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glGenerateMipmap(GL_TEXTURE_2D);
glEnable(GL_MULTISAMPLE);
//for (int i = 0; i < quad->m_Entries.size(); i++)
{
renderDeferredPass(0);
renderLightPass();
}
glutSwapBuffers();
glutPostRedisplay();
}
For complete implementation refer following
https://github.com/PixelClear/Deferred-renderer
I have above code where we store light information in SSBO so this demo has 32 lights but can easily extended to many.
The problem is due to the fixed "ambient" term being repeated for the # of lights that overlap the scene.
The shader contains:
vec3 lighting = Diffuse * 0.1; // hard-coded ambient component
This effectively re-adds albedo everytime a light overlaps.
The old code had the following sum:
vec3 lighting = Diffuse * 0.1;
foreach (Light l : lights)
lighting += Diffuse * (l's diffuse lighting)
But now with additive blending you have:
foreach (Light l : lights)
lighting += Diffuse * 0.1;
lighting += Diffuse * (l's diffuse lighting)
As such you got the overbrightening of ambient in https://i.ibb.co/gMBtM6c/With-Blend.png
To fix this you need to separate the (Diffuse * 0.1) term into a separate shader. You would have 1 draw call to apply ambient, then n draw calls for n lights.
The algorithm on the C++ side would then look like:
Make sure you have additive blend still.
Clear Screen
Set Ambient shader, Draw Quad.
Set Light shader, Do your lighting loop and Draw n Quads for n lights.
EDIT: Also it looks like you aren't reading the right Albedo texture based off of your screenshots. It looks like you are reading the position buffer based off of the colors you're getting.
I am trying to implement shadow maps for point lights. Basically I'm creating a framebuffer and then render all shadow casters on each side of a cubemap texture (which is 6 times) and then read it in the regular rendering pass and determine which pixel is in shadow. I have several questions:
Why do I have to include a color attachment in addition to a depth component in order for my cubemap to get anything rendered to? I tried it without the color attachment and it did not work.
After adding the color attachment, I can see my shadow casters in the cubemap but it seems the shadow comparison is wrong. I am suspecting that one is in NDC while the other isn't.
Here's how I initialize my framebuffer containing the shadow cubemap:
// Create the depth buffer
glGenTextures(1, &mDepthTextureID);
glBindTexture(GL_TEXTURE_2D, mDepthTextureID);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glBindTexture(GL_TEXTURE_2D, 0);
//Create the cubemap texture
glGenTextures(1, &mCubemapTextureID);
glBindTexture(GL_TEXTURE_CUBE_MAP, mCubemapTextureID);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
for (GLuint i = 0; i < 6; ++i)
{
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_R32F, width, height, 0, GL_RED, GL_FLOAT, 0);
}
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
//Create the framebuffer and attach the cubemap texture to it
glGenFramebuffers(1, &mFrameBufferObjectID);
glBindFramebuffer(GL_FRAMEBUFFER, mFrameBufferObjectID);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, mDepthTextureID, 0);
//Disable writes to the color buffer
glDrawBuffer(GL_NONE);
//Disable reads from the color buffer
glReadBuffer(GL_NONE);
GLenum Status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (Status != GL_FRAMEBUFFER_COMPLETE)
{
switch(Status)
{
case GL_FRAMEBUFFER_UNSUPPORTED:
printf("FrameBuffer unsupported error");
return false;
break;
case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
printf("FrameBuffer incomplete attachement");
return false;
break;
default:
printf("GLShadowCubemap error, status: 0x%x\n", Status);
return false;
}
}
//Unbind this
glBindFramebuffer(GL_FRAMEBUFFER, 0);
Here's my shadow's vertex shader: (Only the Position attribute is used)
#version 330 core
layout (location = 0) in vec3 Position;
layout (location = 1) in vec3 Normal;
layout (location = 2) in vec2 TexCoord;
layout (location = 3) in vec3 Tangent;
uniform mat4 gModelMatrix;
uniform mat4 gModelViewProjectionMatrix;
out vec3 WorldPosition;
/*
* Below needs a GS and using layered rendering
void main()
{
gl_Position = gModelMatrix * vec4(Position, 1.0);
}
*/
void main()
{
vec4 pos4 = vec4(Position, 1.0);
gl_Position = gModelViewProjectionMatrix * pos4;
WorldPosition = (gModelMatrix * pos4).xyz;
}
Here's my shadow fragment shader:
#version 330 core
in vec3 WorldPosition;
uniform vec3 gLightPosition;
out float Fragment;
void main()
{
// get distance between fragment and light source
float dist_to_light = length(WorldPosition - gLightPosition);
//gl_FragDepth = dist_to_light;
Fragment = dist_to_light;
}
Additional question here:
I saw that many have said that overriding gl_FragDepth is a bad idea. I kind of know why but what's strange here is that if I were to override the gl_FragDepth manually, nothing gets written to the cubemap. Why?
Here's how I render all the regular stuff (the variable i is an index to my lights array)
mShadowCubemapFBOs[i].ViewportChange();
mShadowMapTechnique.SetLightPosition(light.Position);
const float shadow_aspect = (static_cast<float>(mShadowWidth) / mShadowHeight);
const mat4 shadow_projection_matrix = glm::perspective(90.f, shadow_aspect, 1.f, mShadowFarPlane);
const vector<MeshComponent>& meshes = ComponentManager::Instance().GetMeshComponentPool().GetPool();
for(int layer = 0; layer < 6; ++layer)
{
GLenum cubemap_face = GL_TEXTURE_CUBE_MAP_POSITIVE_X + layer;
mShadowCubemapFBOs[i].Bind(cubemap_face);
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
for(const MeshComponent& mesh : meshes)
{
//the transform_component is referenced ahead of time.
const mat4 model_transform = transform_component->GetTransformMatrix();
mShadowMapTechnique.SetModelViewProjectionMatrix(light.Position, cubemap_face, shadow_projection_matrix, model_transform);
mShadowMapTechnique.SetModelMatrix(model_transform);
mesh.Render();
}
}
Finally here's the regular rendering shader:
#version 330 core
const int MAX_LIGHTS = 8;
const int LIGHT_TYPE_DIRECTIONAL = 0;
const int LIGHT_TYPE_POINT = 1;
const int LIGHT_TYPE_SPOT = 2;
in vec2 TexCoord0;
in vec3 WorldNormal0;
in vec3 WorldPos0;
in vec3 WorldTangent0;
out vec4 FragmentColor;
struct Material
{
vec4 Emissive;
vec4 Ambient;
vec4 Diffuse;
vec4 Specular;
float SpecularPower;
bool UseTexture;
};
struct Light
{
vec3 Position;
vec3 Direction;
vec4 Color; //RGBA
float SpotAngle;
float ConstantAttenuation;
float LinearAttenuation;
float QuadraticAttenuation;
int LightType;
samplerCube ShadowMap; //Cubemap shadows
bool Enabled;
};
struct LightingResult
{
vec4 Diffuse;
vec4 Specular;
};
uniform Material gMaterial;
uniform Light gLights[MAX_LIGHTS];
uniform sampler2D gTextureSampler0;
uniform sampler2D gNormalMap;
uniform bool gEnableNormalMap;
uniform vec3 gEyeWorldPos;
float CalculateShadowFactor(vec3 frag_pos, Light light)
{
vec3 fragment_to_light = frag_pos - light.Position;
float sample_distance = texture(light.ShadowMap, fragment_to_light).r;
float distance = length(fragment_to_light);
if (distance < sample_distance + 0.001)
{
return 1.0; // Inside the light
}
else
{
return 0.5; // Inside the shadow
}
}
//L - Light direction vector from pixel to light source
//N - Normal at the pixel
vec4 CalculateDiffuse(Light light, vec3 L, vec3 N)
{
float n_dot_l = max(0, dot(N, L));
return light.Color * n_dot_l;
}
//V - View vector
//L - Light direction vector from pixel to light source
//N - Normal at the pixel
vec4 CalculateSpecular(Light light, vec3 V, vec3 L, vec3 N)
{
//Phong lighting
vec3 R = normalize(reflect(-L, N));
float r_dot_v = max(0, dot(R, V));
return light.Color * pow(r_dot_v, max(0.4, gMaterial.SpecularPower));
}
float CalculateAttenuation(Light light, float distance)
{
return 1.0 / (light.ConstantAttenuation + light.LinearAttenuation * distance + light.QuadraticAttenuation * distance * distance);
}
//V - View vector
//P - Position of pixel
//N - Normal of pixel
LightingResult CalculatePointLight(Light light, vec3 V, vec3 P, vec3 N)
{
LightingResult result;
result.Diffuse = vec4(0.0, 0.0, 0.0, 1.0);
result.Specular = vec4(0.0, 0.0, 0.0, 1.0);
vec3 L = light.Position - P;
float distance = length(L);
L = normalize(L);
float attenuation = CalculateAttenuation( light, distance );
result.Diffuse = CalculateDiffuse(light, L, N) * attenuation;
result.Specular = CalculateSpecular(light, V, L, N) * attenuation;
return result;
}
//V - View vector
//P - Position of pixel
//N - Normal of pixel
LightingResult CalculateDirectionalLight(Light light, vec3 V, vec3 P, vec3 N)
{
LightingResult result;
result.Diffuse = vec4(0.0, 0.0, 0.0, 1.0);
result.Specular = vec4(0.0, 0.0, 0.0, 1.0);
vec3 L = -light.Direction;
result.Diffuse = CalculateDiffuse(light, L, N);
result.Specular = CalculateSpecular(light, V, L, N);
return result;
}
//L - Light vector
//Smoothness increases as angle gets larger
float CalculateSpotCone(Light light, vec3 L)
{
//cos are in radians
float min_cos = cos(light.SpotAngle);
float max_cos = (min_cos + 1.0f) / 2.0f;
float cos_angle = dot(light.Direction, -L); //negated L such that as we move towards the edge, intensity decreases
return smoothstep(min_cos, max_cos, cos_angle);
}
//V - View vector
//P - Position of pixel
//N - Normal of pixel
LightingResult CalculateSpotLight(Light light, vec3 V, vec3 P, vec3 N)
{
LightingResult result;
result.Diffuse = vec4(0.0, 0.0, 0.0, 1.0);
result.Specular = vec4(0.0, 0.0, 0.0, 1.0);
vec3 L = light.Position - P;
float distance = length(L);
L = normalize(L);
float attenuation = CalculateAttenuation(light, distance);
float spot_intensity = CalculateSpotCone(light, L);
result.Diffuse = CalculateDiffuse(light, L, N) * attenuation * spot_intensity;
result.Specular = CalculateSpecular(light, V, L, N) * attenuation * spot_intensity;
return result;
}
//P - Position of pixel
//N - Normal of pixel
LightingResult CalculateLighting(vec3 P, vec3 N)
{
vec3 V = normalize(gEyeWorldPos - P);
LightingResult total_result;
total_result.Diffuse = vec4(0, 0, 0, 1.0);
total_result.Specular = vec4(0, 0, 0, 1.0);
for(int i = 0; i < MAX_LIGHTS; ++i)
{
if(!gLights[i].Enabled)
{
continue;
}
LightingResult result;
result.Diffuse = vec4(0, 0, 0, 1.0);
result.Specular = vec4(0, 0, 0, 1.0);
float shadow_factor = 1.0;
switch(gLights[i].LightType)
{
case LIGHT_TYPE_DIRECTIONAL:
result = CalculateDirectionalLight(gLights[i], V, P, N);
break;
case LIGHT_TYPE_POINT:
result = CalculatePointLight(gLights[i], V, P, N);
shadow_factor = CalculateShadowFactor(P, gLights[i]);
break;
case LIGHT_TYPE_SPOT:
result = CalculateSpotLight(gLights[i], V, P, N);
shadow_factor = CalculateShadowFactor(P, gLights[i]);
break;
}
total_result.Diffuse += (result.Diffuse * shadow_factor);
total_result.Specular += (result.Specular * shadow_factor);
}
total_result.Diffuse = clamp(total_result.Diffuse, 0, 1);
total_result.Specular = clamp(total_result.Specular, 0, 1);
return total_result;
}
vec3 CalculateNormalMapNormal()
{
vec3 normal = normalize(WorldNormal0);
vec3 tangent = normalize(WorldTangent0);
tangent = normalize(tangent - dot(tangent, normal) * normal); //remove components from the normal vector. This is needed for non-uniform scaling
vec3 bi_tangent = cross(tangent, normal);
vec3 bump_map = texture(gNormalMap, TexCoord0).xyz;
bump_map = 2.0 * bump_map - vec3(1.0, 1.0, 1.0); //Remaps the values
mat3 TBN = mat3(tangent, bi_tangent, normal);
vec3 actual_normal = TBN * bump_map;
return normalize(actual_normal);
}
void main()
{
vec3 pixel_normal = normalize(WorldNormal0);
vec4 texture_color = vec4(0, 0, 0, 1);
if(gMaterial.UseTexture)
{
texture_color = texture( gTextureSampler0, TexCoord0 );
}
if(gEnableNormalMap)
{
pixel_normal = CalculateNormalMapNormal();
}
LightingResult light_result = CalculateLighting(WorldPos0, pixel_normal);
vec4 diffuse_color = gMaterial.Diffuse * light_result.Diffuse;
vec4 specular_color = gMaterial.Specular * light_result.Specular;
FragmentColor = (gMaterial.Emissive + gMaterial.Ambient + diffuse_color + specular_color) * texture_color;
//FragmentColor = texture_color;
//temp test
//vec3 fragment_to_light = WorldPos0 - gLights[1].Position;
//FragmentColor = vec4(vec3(texture(gLights[1].ShadowMap, fragment_to_light).r / gFarPlane), 1.0);
}
What am I doing wrong? I see that I am storing the distance from fragment to light in world space and it is written to a color buffer (not the depth buffer) and so it shouldn't be in NDC. Finally when I am comparing it, it's also in world space .... Why are the shadows off? It appears as if the shadows are way larger than they should be so the entire scene is covered with shadow and it appears that what should be the size of shadow is actually covered in light.
Picture of the shadow cubemap:
Picture of the scene (only the helicopter will cast shadow):
Thanks!
After some debugging, I found out my problems:
glPerspective takes fov as radians, not degrees even though it's documentation says it's only in radians if FORCE_RADIANS is defined (I did not define that)
The cubemap for shadow require the clear color to be (FLT_MAX, FLT_MAX, FLT_MAX, 1.0) such that everything is NOT in shadow by default.
I implemented a new rendering pipeline in my engine and rendering is broken now. When I directly draw a texture of the G-Buffer to screen, it shows up correctly. So the G-Buffer is fine. But somehow the lighting pass makes trouble. Even if I don't use the resulting texture of it but try to display albedo from G-Buffer after the lighting pass, it shows a solid gray color.
I can't explain this behavior and the strange thing is that there are no OpenGL errors at any point.
Vertex Shader to draw a fullscreen quad.
#version 330
in vec4 vertex;
out vec2 coord;
void main()
{
coord = vertex.xy;
gl_Position = vertex * 2.0 - 1.0;
}
Fragment Shader for lighting.
#version 330
in vec2 coord;
out vec3 image;
uniform int type = 0;
uniform sampler2D positions;
uniform sampler2D normals;
uniform vec3 light;
uniform vec3 color;
uniform float radius;
uniform float intensity = 1.0;
void main()
{
if(type == 0) // directional light
{
vec3 normal = texture2D(normals, coord).xyz;
float fraction = max(dot(normalize(light), normal) / 2.0 + 0.5, 0);
image = intensity * color * fraction;
}
else if(type == 1) // point light
{
vec3 pixel = texture2D(positions, coord).xyz;
vec3 normal = texture2D(normals, coord).xyz;
float dist = max(distance(pixel, light), 1);
float magnitude = 1 / pow(dist / radius + 1, 2);
float cutoff = 0.4;
float attenuation = clamp((magnitude - cutoff) / (1 - cutoff), 0, 1);
float fraction = clamp(dot(normalize(light - pixel), normal), -1, 1);
image = intensity * color * attenuation * max(fraction, 0.2);
}
}
Targets and samplers for the lighting pass. Texture ids are mapped to attachment respectively shader location.
unordered_map<GLenum, GLuint> targets;
targets.insert(make_pair(GL_COLOR_ATTACHMENT2, ...)); // light
targets.insert(make_pair(GL_DEPTH_STENCIL_ATTACHMENT, ...)); // depth and stencil
unordered_map<string, GLuint> samplers;
samplers.insert(make_pair("positions", ...)); // positions from G-Buffer
samplers.insert(make_pair("normals", ...)); // normals from G-Buffer
Draw function for lighting pass.
void DrawLights(unordered_map<string, GLuint> Samplers, GLuint Program)
{
auto lis = Entity->Get<Light>();
glClear(GL_COLOR_BUFFER_BIT);
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE);
glUseProgram(Program);
int n = 0; for(auto i : Samplers)
{
glActiveTexture(GL_TEXTURE0 + n);
glBindTexture(GL_TEXTURE_2D, i.second);
glUniform1i(glGetUniformLocation(Program, i.first.c_str()), n);
n++;
}
mat4 view = Entity->Get<Camera>(*Global->Get<unsigned int>("camera"))->View;
for(auto i : lis)
{
int type = i.second->Type == Light::DIRECTIONAL ? 0 : 1;
vec3 pos = vec3(view * vec4(Entity->Get<Form>(i.first)->Position(), !type ? 0 : 1));
glUniform1i(glGetUniformLocation(Program, "type"), type);
glUniform3f(glGetUniformLocation(Program, "light"), pos.x, pos.y, pos.z);
glUniform3f(glGetUniformLocation(Program, "color"), i.second->Color.x, i.second->Color.y, i.second->Color.z);
glUniform1f(glGetUniformLocation(Program, "radius"), i.second->Radius);
glUniform1f(glGetUniformLocation(Program, "intensity"), i.second->Intensity);
glBegin(GL_QUADS);
glVertex2i(0, 0);
glVertex2i(1, 0);
glVertex2i(1, 1);
glVertex2i(0, 1);
glEnd();
}
glDisable(GL_BLEND);
glActiveTexture(GL_TEXTURE0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindTexture(GL_TEXTURE_2D, 0);
}
I found the error and it was such a stupid one. The old rendering pipeline bound the correct framebuffer before calling the draw function of that pass. But the new one didn't so each draw function had to do that itself. Therefore I wanted to update all draw function, but I missed the draw function of the lighting pass.
Therefore the framebuffer of the G-Buffer was still bound and the lighting pass changed its targets.
Thanks to you guys, you had no change to find that error, since I hadn't posted my complete pipeline system.
i'm trying to bind 2 textures for my shader. But for some reason it always seems to take the last image that i defined. Am i doing something wrong?
GLuint textures[2];
glEnable(GL_TEXTURE_2D);
glGenTextures(2, textures);
glBindTexture(GL_TEXTURE_2D, textures[0]);
glfwLoadTexture2D("C:\\front.tga", GLFW_BUILD_MIPMAPS_BIT);
glBindTexture(GL_TEXTURE_2D, textures[1]);
glfwLoadTexture2D("C:\\reflect.tga", GLFW_BUILD_MIPMAPS_BIT);
In this case i see 'reflect.tga' for both the reflection and refraction in my shader...
const vec3 Xunitvec = vec3 (1.0, 0.0, 0.0);
const vec3 Yunitvec = vec3 (0.0, 1.0, 0.0);
uniform vec3 BaseColor;
uniform float Depth;
uniform float MixRatio;
// need to scale our framebuffer - it has a fixed width/height of 2048
uniform float FrameWidth;
uniform float FrameHeight;
uniform sampler2D EnvMap;
uniform sampler2D RefractionMap;
varying vec3 Normal;
varying vec3 EyeDir;
varying vec4 EyePos;
varying float LightIntensity;
void main (void)
{
// Compute reflection vector
vec3 reflectDir = reflect(EyeDir, Normal);
// Compute altitude and azimuth angles
vec2 index;
index.y = dot(normalize(reflectDir), Yunitvec);
reflectDir.y = 0.0;
index.x = dot(normalize(reflectDir), Xunitvec) * 0.5;
// Translate index values into proper range
if (reflectDir.z >= 0.0)
index = (index + 1.0) * 0.5;
else
{
index.t = (index.t + 1.0) * 0.5;
index.s = (-index.s) * 0.5 + 1.0;
}
// if reflectDir.z >= 0.0, s will go from 0.25 to 0.75
// if reflectDir.z < 0.0, s will go from 0.75 to 1.25, and
// that's OK, because we've set the texture to wrap.
// Do a lookup into the environment map.
vec3 envColor = vec3 (texture2D(EnvMap, index));
// calc fresnels term. This allows a view dependant blend of reflection/refraction
float fresnel = abs(dot(normalize(EyeDir), Normal));
fresnel *= MixRatio;
fresnel = clamp(fresnel, 0.1, 0.9);
// calc refraction
vec3 refractionDir = normalize(EyeDir) - normalize(Normal);
// Scale the refraction so the z element is equal to depth
float depthVal = Depth / -refractionDir.z;
// perform the div by w
float recipW = 1.0 / EyePos.w;
vec2 eye = EyePos.xy * vec2(recipW);
// calc the refraction lookup
index.s = (eye.x + refractionDir.x * depthVal);
index.t = (eye.y + refractionDir.y * depthVal);
// scale and shift so we're in the range 0-1
index.s = index.s / 2.0 + 0.5;
index.t = index.t / 2.0 + 0.5;
// as we're looking at the framebuffer, we want it clamping at the edge of the rendered scene, not the edge of the texture,
// so we clamp before scaling to fit
float recip1k = 1.0 / 2048.0;
index.s = clamp(index.s, 0.0, 1.0 - recip1k);
index.t = clamp(index.t, 0.0, 1.0 - recip1k);
// scale the texture so we just see the rendered framebuffer
index.s = index.s * FrameWidth * recip1k;
index.t = index.t * FrameHeight * recip1k;
vec3 RefractionColor = vec3 (texture2D(RefractionMap, index));
// Add lighting to base color and mix
vec3 base = LightIntensity * BaseColor;
envColor = mix(envColor, RefractionColor, fresnel);
envColor = mix(envColor, base, 0.2);
gl_FragColor = vec4 (envColor, 1.0);
}
A sampler uniform does not bind a texture object but a texture unit. And texture objects are bound to texture units. So the sequence for binding a texture to a shader is
glActiveTexture(GL_TEXTURE0 + texture_unit1);
glBindTexture(GL_TEXTURE_..., texture_object1);
glActiveTexture(GL_TEXTURE0 + texture_unit2);
glBindTexture(GL_TEXTURE_..., texture_object2);
glUniform1i(sampler1_location, texture_unit1);
glUniform1i(sampler2_location, texture_unit2);
Texture Units are in the range 0...GL_MAX_TEXTURE_UNITS.
And this is result when I invert the tangent vector right after transferring it to vertex shader:
The "shadow" is in the wrong place.
(And it works only when I rotate it through Y axis so the last image seem to present a good parallax mapped cube)
IM SURE IT IS NOT A TANGENT VECTOR OR TEXTURE COORDINATES PROBLEM
Because
I used exactly the same tangent calculation functions and exactly the same cube position, normal and texture coordinate data as in working demo.
After all, I exported arrays with position/texcoord/normal/tangent data into a .txt file and I saw what I exactly expected (and what I expected is the same pos/tex/norm data as in working demo, including calculated tangents which I managed to export from working demo).
The next argument is, I copied my shader code to a working demo and it still works.
Other one is, I tried multiple ways to render this cube.
I tried VBO with glVertexAttribPointer, I tried VBO with saving tangent as other texture coordinate (as in the demo), I tried DisplayList with glVertexAttrib4f. Result is... EXACTLY THE SAME.
Height map is loading correctly, I tried to set it as a diffuse map and it looked OK.
glGetError() gives me No Errors and shader compile logs says so.
It is probably something with camera or init states.
Maybe posting an init code will help.
void CDepthBase::OpenGLSet() {
glEnable( GL_TEXTURE_2D );
glShadeModel( GL_SMOOTH );
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClearDepth( 1.0f );
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glDepthFunc( GL_LEQUAL );
glEnable(GL_DEPTH_TEST);
glBlendFunc( GL_ONE, GL_ONE );
GLfloat ratio;
glViewport(0, 0, ResolutionWidth, ResolutionHeight);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f, ResolutionWidth / (float)ResolutionHeight, 0.1f, 900.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
if (GLEW_OK != glewInit()) {
MBX("Failed to init GLEW.", "Error");
}
if (glewIsSupported("GL_ARB_vertex_buffer_object")) {
VBO_supported = true;
} else VBO_supported = false;
glHint( GL_FOG_HINT, GL_DONT_CARE );
glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
glShadeModel(GL_SMOOTH);
glAlphaFunc(GL_ALWAYS, 0);
}
By the way, I'm using GL Extension Wrangler with extensions.
Shader code & log (this exported file contains code which was directly passed to glShaderSource):
Vertex shader was successfully compiled to run on hardware.
Fragment shader was successfully compiled to run on hardware.
Fragment shader(s) linked, vertex shader(s) linked.
------------------------------------------------------------------------------------------
varying vec3 lightDir;
varying vec3 viewDir;
attribute vec4 tangent;
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_TexCoord[0] = gl_MultiTexCoord0;
vec3 vertexPos = vec3(gl_ModelViewMatrix * gl_Vertex);
vec3 tn = tangent.xyz;
vec3 n = normalize(gl_NormalMatrix * gl_Normal);
vec3 t = normalize(gl_NormalMatrix * tangent.xyz);
vec3 b = cross(t, n) * -tangent.w;
mat3 tbnMatrix = mat3(t.x, b.x, n.x,
t.y, b.y, n.y,
t.z, b.z, n.z);
lightDir = (gl_LightSource[0].position.xyz - vertexPos) / 100.0;
lightDir = tbnMatrix * lightDir;
viewDir = -vertexPos;
viewDir = tbnMatrix * viewDir;
}
-----------------------------------------------------------------------------------------
varying vec3 lightDir;
varying vec3 viewDir;
uniform sampler2D diffuseMap;
uniform sampler2D normalMap;
uniform sampler2D heightMap;
uniform float scale;
uniform float bias;
void main()
{
vec3 v = normalize(viewDir);
vec2 TexCoord = gl_TexCoord[0].st;
{
float height = texture2D(heightMap, gl_TexCoord[0].st).r;
height = height * scale + bias;
TexCoord = gl_TexCoord[0].st + (height * v.xy);
}
vec3 l = lightDir;
float atten = max(0.0, 1.0 - dot(l, l));
l = normalize(l);
vec3 n = normalize(texture2D(normalMap, TexCoord).rgb * 2.0 - 1.0);
vec3 h = normalize(l + v);
float nDotL = max(0.0, dot(n, l));
float nDotH = max(0.0, dot(n, h));
float power = (nDotL == 0.0) ? 0.0 : pow(nDotH, gl_FrontMaterial.shininess);
vec4 ambient = gl_FrontLightProduct[0].ambient * atten;
vec4 diffuse = gl_FrontLightProduct[0].diffuse * nDotL * atten;
vec4 specular = gl_FrontLightProduct[0].specular * power * atten;
vec4 color = gl_FrontLightModelProduct.sceneColor + ambient + diffuse + specular;color *= texture2D(diffuseMap,TexCoord);
gl_FragColor = color ;
}
Uniforms are working correctly because results are the same if I switch them with constant values.
Compiling shader:
void __Shader::import(){
if(imported) __Shader::~__Shader();
v = glCreateShader(GL_VERTEX_SHADER);
f = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(v, 1, (const GLchar **)&vsrc.cstr,NULL);
glShaderSource(f, 1, (const GLchar **)&fsrc.cstr,NULL);
glCompileShader(v);
glCompileShader(f);
p = glCreateProgram();
glAttachShader(p,v);
glAttachShader(p,f);
if(_flags & NORMAL_MAPPING)
glBindAttribLocation(p, ATTRIB_TANGENT, "tangent");
glLinkProgram(p);
if(_flags & DIFFUSE_MAPPING)
diffuseUni.loc = glGetUniformLocation(p, "diffuseMap");
if(_flags & NORMAL_MAPPING)
normalUni.loc = glGetUniformLocation(p, "normalMap");
if(_flags & PARALLAX_MAPPING)
heightUni.loc = glGetUniformLocation(p, "heightMap");
if(_flags & SPECULAR_MAPPING)
specularUni.loc = glGetUniformLocation(p, "specularMap");
imported = true;
}
Setting attribute in VBO:
if(tangents.size() > 0){
buffered |= 3;
glGenBuffers(1, &VBO_tangent);
glBindBuffer(GL_ARRAY_BUFFER, VBO_tangent);
glBufferData(GL_ARRAY_BUFFER, tangents.size()*sizeof(tangent), tangents.get_ptr(), GL_STATIC_DRAW);
}
// and in draw:
if(buffered & 3) {
glBindBuffer(GL_ARRAY_BUFFER, VBO_tangent);
glVertexAttribPointer(__Shader::ATTRIB_TANGENT, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(__Shader::ATTRIB_TANGENT);
}
and a small note
for(int i = 0; i < responders.size(); ++i)
if(strstr(responders[i].idea, "tangent problem"))
responders[i].please_dont_talk();
Just tell me your other ideas about what can be the reason of those bad results.
Wheew... already solved it. The problem was with loading texture files even though I did not see any disorders with diffuse mapping or even with diffuse+normal mapping. I was using IMG_Load from SDL, maybe I used it wrong way but it did not work for me. It was probably normal map messed up.
bad texture import code:
if(imported || filenamez.length() < 1) return;
SDL_Surface* surface = 0;
surface = IMG_Load(filenamez.c_str());
if (surface) {
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
bool endianess = filenamez.substr(filenamez.length()-4) == ".jpg";
glTexImage2D(GL_TEXTURE_2D, 0, 3, surface->w, surface->h, 0,
(endianess ? GL_RGB : GL_BGR), GL_UNSIGNED_BYTE, surface->pixels);
}
BEWARE !
I'm now using HBITMAP-based texture loading taken from dhpoware demo which I was talking about. And it works fine.
peace.
After 2-3 days of hard debugging, let me feel a little bit of euphoria.
Oh, I'd forget, the final result: