A computing device for rendering an image at a full resolution, comprising: a memory storing one or more parameters or instructions for executing an operating system and one or more applications; a graphics processing unit, GPU, for rendering frames of the one or more applications for display on a display device coupled to the computing device, the GPU including GPU depth data ; at least one processor coupled to the memory, and the GPU, wherein the at least one processor is configured to: render an occlusion geometry at a reduced resolution lower than the full resolution; sample a depth value of pixels of the occlusion geometry; pre-populate the GPU depth data based on the sampled depth values prior to a full resolution rendering process to generate the image at the full resolution, wherein the GPU depth data includes hierarchical depth buffer metadata ; and bias the sampled depth values toward a further depth for pre-populating the GPU depth data, wherein the GPU is configured to: cull at least one tile or pixel from a full resolution rendering process in response to a depth of the at least one tile or pixel being further than a corresponding depth value in the GPU depth data; and perform the full resolution rendering process on remaining tiles or pixels to generate the image at the full resolution. a memory storing one or more parameters or instructions for executing an operating system and one or more applications; a graphics processing unit, GPU, for rendering frames of the one or more applications for display on a display device coupled to the computing device, the GPU including GPU depth data ; at least one processor coupled to the memory, and the GPU, wherein the at least one processor is configured to: render an occlusion geometry at a reduced resolution lower than the full resolution; sample a depth value of pixels of the occlusion geometry; pre-populate the GPU depth data based on the sampled depth values prior to a full resolution rendering process to generate the image at the full resolution, wherein the GPU depth data includes hierarchical depth buffer metadata ; and bias the sampled depth values toward a further depth for pre-populating the GPU depth data, render an occlusion geometry at a reduced resolution lower than the full resolution; sample a depth value of pixels of the occlusion geometry; pre-populate the GPU depth data based on the sampled depth values prior to a full resolution rendering process to generate the image at the full resolution, wherein the GPU depth data includes hierarchical depth buffer metadata ; and bias the sampled depth values toward a further depth for pre-populating the GPU depth data, wherein the GPU is configured to: cull at least one tile or pixel from a full resolution rendering process in response to a depth of the at least one tile or pixel being further than a corresponding depth value in the GPU depth data; and perform the full resolution rendering process on remaining tiles or pixels to generate the image at the full resolution. cull at least one tile or pixel from a full resolution rendering process in response to a depth of the at least one tile or pixel being further than a corresponding depth value in the GPU depth data; and perform the full resolution rendering process on remaining tiles or pixels to generate the image at the full resolution. <EOS>