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我想使用深度缓冲区通过使用 OpenGL 2.1 / GLSL 1.2 将眼睛空间中粒子的深度值存储在 2D 纹理中。

到目前为止，我找到了一种使用颜色缓冲区的方法

// create texture
glGenTextures(1, &g_hDepthTexture);
glBindTexture(GL_TEXTURE_2D, g_hDepthTexture);
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_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB, g_windowWidth, g_windowHeight, 0, GL_RGBA, GL_FLOAT, 0);
// create framebuffer
glGenFramebuffersEXT(1, &g_hFBO);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, g_hFBO);glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, g_hDepthTexture, 0);

但是，我不需要 BGA 组件。因此，我尝试使用深度缓冲区，但下面的代码将纹理中的每个值钳制为 0...1

// create texture
glGenTextures(1, &g_hDepthTexture);
glBindTexture(GL_TEXTURE_2D, g_hDepthTexture);
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_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, g_windowWidth, g_windowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);  // create framebuffer
glGenFramebuffersEXT(1, &g_hFBO);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, g_hFBO);

glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);

glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, g_hDepthTexture, 0);

我想知道如何使用深度缓冲区（可能是如何选择正确的内部格式/格式），以便不限制纹理值。

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1 回答 1

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Normalized integer image formats are always clamped. That's why they're normalized integers. If you want an unclamped format, then you need floating point values.

I would suggest using an actual 1-channel floating-point image format, such as GL_R32F. Maybe GL_R16F, depending on how much precision I need. If you don't have GL 3.x hardware, you may be able to use GL_LUMINANCE32F_EXT, depending on what extensions are available.

BTW, if you're doing this for deferred rendering, don't bother. You can actually calculate the eye-space point directly from the regular depth buffer. Yes, really.

于 2012-03-05T17:15:52.717 回答