I know one thing, it'll boost performance on ATI DX10.1 enabled cards, looks at the performance increase Asassins Creed got from running in DX10.1 vs DX10
What exactly are you pointing to in that doc?
IIRC thats more or less what happened with Assassins Creed.I'm not sure, but here and there are statements, that it would be like Supersampling.
Crysis creates its Depth Buffer first. And this Depth Buffer is used later for almost everything. With a "MSAA Depth Buffer" you will do shading not only per-pixel but per-sample.
With a "MSAA Depth Buffer" you will do shading not only per-pixel but per-sample.
Would a "MSAA depth buffer" allow AA to work on the foliage?
It's an option, but certainly not required. And I doubt many developers would actually do that. The two most common choices would be to either grab one sample, or resolve the depth buffer to a non-MSAA buffer and use that.
.
Just to clarify, MSAA depth buffers are as old as MSAA itself. You need one to use MSAA at all since the depth buffer and color buffer must have matching MSAA mode. What's new in DX10.1 is a sampleable MSAA depth buffer. This doesn't affect foliage in any particular way. However, DX10.1 also offers per-sample fragment shader evaluation, which can indeed be useful for foliage and allow proper antialiasing on alpha edges. It would be better looking that alpha-to-coverage, but at a performance cost. DX10.1 also has a programmable sample mask, which you could use to create your own alpha-to-coverage equivalent implementation, where you could use a better algorithm than the built-in hardware implementation, and should not be much slower than regular alpha-to-coverage. Also, that way you can return a useful non-coverage alpha value from the shader, which is often a very desirable feature.
Crysis' atmospheric effects like the global fog, fog volumes and soft z buffered particles and SSAO are using the same Z values from the Depth Buffer. Wouldn't your options break the precision of these effects?
Crysis' atmospheric effects like the global fog, fog volumes and soft z buffered particles and SSAO are using the same Z values from the Depth Buffer. Wouldn't your options break the precision of these effects?