Halo 2: Able to see other objects through objects close to you

[Alastair0100]

Also can depend on viewing angle aswell as how close objects are to you from my testing

Title: 4d530064

[Shoegzer]

Confirmed in testing here too.

Relevant test specs:

• OS: Linux Mint 20.3 / kernel 5.131
• GPU: NVidia GTX 3070 / driver 470.86
• Commit tested: 3fd1521

[Triticum0]

This also affects Wallace & Gromit in Project Zoo, Miami Vice, Tom Clancy's Splinter Cell and Serious Sam

[RageXbox]

Here’s a log for this.
Halo 2 seethrough.log

[abaire]

This looks like it may be a depth buffer precision issue, stepping through the draws in renderdoc I see depth buffer values for the more distant draws that are suspiciously close to but less than the nearby correct nearer geometry with odd discontinuities (e.g., if I follow the plane of a wall that is being cut out, I see values that follow a linear trend then jump to higher values where the earlier draw is peeking through, then resume within the expected interpolated range after the slice).

Halo2 uses a non-standard clip range:

nv2a_pgraph_method 0: NV20_KELVIN_PRIMITIVE<0x97> -> NV097_SET_CLIP_MIN<0x394> (0x437FFFFF => 255.999985)
nv2a_pgraph_method 0: NV20_KELVIN_PRIMITIVE<0x97> -> NV097_SET_CLIP_MAX<0x398> (0x4B7FFFFF => 16777215.000000)

though it at least uses the same range throughout all of the draws in the frame I traced.

I've previously found that the technique xemu employs to attempt to map screen coords produced by the nv2a shaders back into OpenGL-friendly NDC has some issues when dealing with unusual clip ranges (e.g., #843). This may be part of what is happening here.

[Shootfast]

Not sure if this is helpful at all, but in my naive attempt to debug this issue in Renderdoc, I found that commenting out this line of the vertex shader completely fixes the "see-through" issue (though also adds other problems).

Might that point away from it being a depth buffer precision issue, and perhaps point towards it being a problem converting the screen space to clip space?

[polymetal0]

Thanks to your comment, I accidentally got Skybox working!