I'm rendering a frameBuffer texture to another frameBuffer for multiple pass shadows.

The problem is it's not aligning correctly.

Heres my code:

glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO[totalLights]);
glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

shaderMultipassShadows.Use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, depthCubemap[0]);

glUniform1i(glGetUniformLocation(shaderMultipassShadows.Program, "depthMap"), 0);
RenderQuad();
glBindFramebuffer(GL_FRAMEBUFFER, 0);

geometry shade:

#version 330 core
layout (triangles) in;
layout (triangle_strip, max_vertices=18) out;

void main()
{
for(int face = 0; face < 6; ++face)
{
gl_Layer = face; // built-in variable that specifies to which face we render.
for(int i = 0; i < 3; ++i) // for each triangle's vertices
{
gl_Position = gl_in.gl_Position;
EmitVertex();
}
EndPrimitive();
}
}

vertex shader:

#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec2 texCoords;

out vec2 TexCoords;

void main()
{
gl_Position = vec4(position, 1.0f);
TexCoords = texCoords;
}

#version 330 core

in vec2 TexCoords;
out vec4 FragColor;
uniform samplerCube depthMap;

void main()
{
FragColor = textureCube(depthMap, vec3(TexCoords, 1.0f));
}

Thank you.

Solved:

for (GLuint i = 0; i < 6; ++i)
{
glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO[totalLights] + i);
glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

shaderMultipassShadows.Use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, depthCubemap[0] + i);

glUniform1i(glGetUniformLocation(shaderMultipassShadows.Program, "depthMap"), 0);
RenderQuad();
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

No, still not working.

How do I do this?

Im using this geometry shader code:

#version 330 core
layout (triangles) in;
layout (triangle_strip, max_vertices=18) out;

uniform mat4 shadowTransforms[6];

out vec4 FragPos; // FragPos from GS (output per emitvertex)
out vec2 TexCoords;
void main()
{
for(int face = 0; face < 6; ++face)
{
gl_Layer = face; // built-in variable that specifies to which face we render.
for(int i = 0; i < 3; ++i) // for each triangle's vertices
{
FragPos = gl_in.gl_Position;
gl_Position = shadowTransforms[face] * FragPos;
//TexCoords = vec2( 0.5, 0.5 );
EmitVertex();
}
EndPrimitive();
}

And this code for the transforms;

// 0. Create depth cubemap transformation matrices
std::vector<glm::mat4> shadowTransforms;
shadowTransforms.push_back(glm::lookAt(glm::vec3(1.0f, 1.0f, 1.0f), glm::vec3(1.0, 0.0, 0.0), glm::vec3(0.0, -1.0, 0.0)));
shadowTransforms.push_back(glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(-1.0, 0.0, 0.0), glm::vec3(0.0, -1.0, 0.0)));
shadowTransforms.push_back(glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0, 1.0, 0.0), glm::vec3(0.0, 0.0, 1.0)));
shadowTransforms.push_back(glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0, -1.0, 0.0), glm::vec3(0.0, 0.0, -1.0)));
shadowTransforms.push_back(glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0, 0.0, 1.0), glm::vec3(0.0, -1.0, 0.0)));
shadowTransforms.push_back(glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0, 0.0, -1.0), glm::vec3(0.0, -1.0, 0.0)));

for (GLuint i = 0; i < 6; ++i)
glUniformMatrix4fv(glGetUniformLocation(shaderMultipassShadows.Program, ("shadowTransforms[" + std::to_string(i) + "]").c_str()), 1, GL_FALSE, glm::value_ptr(shadowTransforms));

If i play about with the eye matrixes the shadows get rendered in different positions but Idon't know the correct values.

Any ideas?