OpenGL Uniform buffers?

Question

I'm trying to use uniform buffers but it doesn't work as supposed. I have two uniform buffers, one is lighting and the other is for material. The problem is that the colors aren't what they are supposed to be and they change every time I move the camera. This problem didn't exist when I used normal uniforms. Here's pictures to show what I mean: When using uniform buffers and when using normal uniforms!

This is my fragment shader:

#version 400 // Fragment Shader
uniform layout(std140);

in vec3 EyePosition;
in vec3 EyeNormal;
in vec2 TexCoord;

out vec4 FragColor;

uniform sampler2D Texture;

uniform LightBlock
{
    vec4 Position;
    vec4 Intensity;
} Light;

uniform MaterialBlock
{
    vec4 Ambient;
    vec4 Diffuse;
} Material;

vec4 PointLight(in int i, in vec3 ECPosition, in vec3 ECNormal)
{
    vec3 n = normalize(ECNormal);
    vec3 s = normalize(Light.Position.xyz - ECPosition);

    return Light.Intensity * (Material.Ambient + Material.Diffuse * max(dot(s, n), 0.0));
}

void main()
{
    FragColor  = texture(Texture, TexCoord);
    FragColor *= PointLight(0, EyePosition, EyeNormal);
}

I'm not sure I have done everything right but here's how I create the uniform buffers:

glGenBuffers(1, &light_buffer);
glGenBuffers(1, &material_buffer);

glBindBuffer(GL_UNIFORM_BUFFER, light_buffer);
glBufferData(GL_UNIFORM_BUFFER, sizeof(LightBlock), nullptr, GL_DYNAMIC_DRAW);

glBindBuffer(GL_UNIFORM_BUFFER, material_buffer);
glBufferData(GL_UNIFORM_BUFFER, sizeof(MaterialBlock), nullptr, GL_DYNAMIC_DRAW);

GLuint program = Shaders.GetProgram();

light_index = glGetUniformBlockIndex(program, "LightBlock");
material_index = glGetUniformBlockIndex(program, "MaterialBlock");

glUniformBlockBinding(program, light_index, 0);
glUniformBlockBinding(program, material_index, 1);

glBindBufferBase(GL_UNIFORM_BUFFER, 0, light_buffer);
glBindBufferBase(GL_UNIFORM_BUFFER, 1, material_buffer);

EDIT: Here's how I fill the buffers:

// Global structures
struct LightBlock
{
    Vector4 Position; // Vector4 is a vector class I made
    Vector4 Intensity;
};

struct MaterialBlock
{
    Vector4 Ambient;
    Vector4 Diffuse;
};

// This is called for every object rendered
LightBlock Light;
Light.Position = Vector3(0.0f, 5.0f, 5.0f) * Camera.GetCameraMatrix();
Light.Intensity = Vector4(1.0f);

glBindBuffer(GL_UNIFORM_BUFFER, light_buffer);
glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(LightBlock), &Light);

MaterialBlock Material;
Material.Diffuse = Vector4(1.0f);
Material.Ambient = Material.Diffuse * Vector4(0.3f);

glBindBuffer(GL_UNIFORM_BUFFER, material_buffer);
glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(MaterialBlock), &Material);

Answer 1

I had the same problem, but only with AMD (not NVIDIA). The funny thing was that the problem only happened when changing the view matrix.

As I had a repeatable problem depending on change of the view matrix, I was able to trace to the root cause (doing arduous trial and error). When changing the view in my application, I allocate and free some OpenGL resources dynamically depending on what is needed. In this process, there is a call to glDeleteBuffers() for buffer 0. If I use a conditional statement so as not to call glDeleteBuffers for buffer 0, then the problem goes away.

According to documentation, buffer 0 will be silently ignored by glDeleteBuffers. My guess is that there is a bug in the AMD drivers.