HDR 渲染管线差异
典型的 HDR 渲染管线和普通渲染管线有什么区别？ （即 bpp 差异？一些额外的后处理步骤？）
What's the difference between a typical HDR rendering pipeline and a normal rendering pipeline? (i.e. bpp differences? Some additional post processing step?)
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HDR 渲染需要使用浮点缓冲区，因此每个像素的字节数之间存在差异。 RGBA8 缓冲区每个像素使用 4 个字节，但 RGBA16F 缓冲区每个像素使用 8 个字节。
当显示浮点缓冲区时，您需要进行一些后处理，以便信号有意义，因为 FP 数字可能超出 [0,1] 范围，您对 FP 缓冲区进行后处理，将其转换为正常的 [0,1] ] RBGA8 缓冲区，这是通过色调映射运算符完成的。
HDR rendering requires the use of floating point buffers, so there is a difference between bytes per pixel. a RGBA8 buffer uses 4 bytes per pixel, but a RGBA16F buffer uses 8 bytes per pixel.
And when displaying the floating point buffer, you need to do some postprocessing so the signal makes sense, since a FP number can be outside the [0,1] range, you postprocess the FP buffer to convert it to a normal [0,1] RBGA8 buffer, and that's done with a tone mapping operator.
管道非常相似。需要记住的是，您现在可以使用 3 个浮点（即 RGB）来表示光源。这允许您将光源亮度设置得更亮或更暗。
正如已经提到的，是的，您需要使用浮点渲染目标。
不要在照明着色器中饱和，因为这会将您限制在 0 到 1 的范围内。
有两种方法可以对图像进行后处理。一种是在写入后备缓冲区之前简单地将范围压缩回 0 到 255 的范围。然而，这完全没有意义，因为它会让你失去 HDR 的意义。更好的办法是编写一个曝光过滤器。
还值得注意的是，大多数人会将相机效果应用于模型后曝光过滤的饱和部分。最常见的形式是“bloom 滤镜”，我们都见过它被过度使用在电影中。然而，您可以使用大量不同的过滤器来提供良好的效果。搜索“条纹滤镜”，寻找一种与绽放相结合的非常有用的效果。
此处提供了大量良好的一般信息。
The pipelines are fairly similar. Things to bear in mind is that you can now use 3 floats (ie RGB) for representing light sources. This allows you to set a light sources brightness SIGNIFICANTLY brighter or dimmer.
As mentioned already yes you need to use a floating point render target.
Do not saturate in your lighting shaders as this clamps you back to the 0 to 1 range.
There are 2 ways to post process the image. One is to simply compress the range back into a 0 to 255 range before writing to the backbuffer. This would be entirely pointless, however, as it would lose you the point of having HDR. The better thing to do is to write an exposure filter.
Its also worth noting that most people will apply camera effects to the saturated sections of models post exposure filtering. The most common form is the "bloom filter" that we've all seen over used in films. There are, however, loads of different filters you can use to provide nice effects. Search for the "Streak filter" for one very useful effect to combine with blooming.
Loads of good general info here.