Conservative rasterization
Rasterization that counts a pixel as covered the moment a triangle touches it at all, rather than requiring the triangle to cross the pixel's centre.
Ordinary rasterization samples at the pixel centre: a triangle that clips a corner but misses the middle simply isn't drawn. Conservative rasterization overestimates coverage instead — every pixel the triangle touches is flagged as hit. An underestimating variant also exists, counting only pixels the triangle fully covers.
Hardware support arrived with Direct3D 12 (tiers 1–3), the NV_conservative_raster extension, and later Vulkan. It is used wherever gaps in coverage are unacceptable: voxelization for global illumination, occlusion and collision tests on the GPU, and generating signed distance fields. The cost is more fragments to shade, so it is switched on selectively.