我正在尝试使用统一缓冲区,但它不能按预期工作。我有两个统一的缓冲区,一个是灯光,另一个是 Material 。问题在于颜色不是应该的颜色,并且每次我移动相机时它们都会改变。当我使用普通 uniform 时,这个问题不存在。这是显示我的意思的图片:When using uniform bufferswhen using normal uniforms!

这是我的片段着色器:

#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);
}

我不确定我是否做对了所有事情,但是这是我创建统一缓冲区的方法:
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);

编辑:这是我填充缓冲区的方式:
// 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);

最佳答案

我也遇到了同样的问题,但是只有AMD(不是NVIDIA)。有趣的是,该问题仅在更改 View 矩阵时才会发生。

由于根据 View 矩阵的更改,我遇到了一个可重复的问题,因此我能够追溯到根本原因(进行了艰苦的尝试和错误)。在应用程序中更改 View 时,我会根据需要动态分配和释放一些OpenGL资源。在此过程中,对缓冲区0调用了glDeleteBuffers()。如果我使用条件语句以便不为缓冲区0调用glDeleteBuffers,那么问题就消失了。

根据文档,缓冲区0将被glDeleteBuffers静默忽略。我的猜测是AMD驱动程序中存在错误。

关于c++ - OpenGL统一缓冲区?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/9155044/

10-11 22:48
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