Alpha-channel problems with NVemulate and renderpath=vertexshader

[Philip Taylor]

When running the game with [NVemulate ​http://developer.nvidia.com/object/nvemulate.html], set to any emulation mode (NV30, NV40, G80), on a GeForce 4, with renderpath=vertexshader, transparent textures look like in the attachment: parts with alpha=255 (e.g. leaf centres) are usually transparent or stripey, and flicker as you zoom in and out. It works correctly when renderpath=fixed.

Looks like some kind of z-accuracy issue, where models use two different implementations of vertex transformation and end up at slightly different z value? (I'm not sure if it's only ever an issue with NVemulate, or if it can affect real hardware too.)

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Milestone Alpha deleted

[Philip Taylor]

vertexshader no longer exists, and anyway it doesn't matter if the game breaks in NVemulate.