Digital Foundry: Lighting can look quite beautiful in WipEout 2048 - can you give us some technical background there?
Chris Roberts: The lighting on PS Vita is virtually identical to the lighting on HD/Fury. Ships are still lit using image-based lighting with blended diffuse and specular probes that we precompute along the track, and weapon effects use the same vertex-based lighting system, although on PS Vita both of these effects are handled by the GPU rather than SPUs as they were on PS3.
It's easier to talk about the differences - the real-time shadows on PS Vita are almost identical with the exception that we decided to use anti-aliased colour buffers for shadow rendering rather than shadow depth buffers.
This allows us to have transparency in our shadows and the memory cost of anti-aliasing is mitigated by the colour buffer only requiring 8 bits per pixel, so a 4xMSAA colour buffer uses the same memory as a 32-bit depth buffer, however it did mean we had to sacrifice self-shadowing on the ships.
The post-effects are slightly improved in WipEout 2048 - tone mapping is more 'correct' because the PS Vita has efficient hardware supported buffer formats, so the exposure control and bloom effects in 2048 are generally better-quality than the HD/Fury counterpart. Also, in 2048 we have longer tracks that tend to require a lot more lightmap texture space - fortunately the SGX supports texture compression with higher compression rates, so even taking the longer tracks into account, there are also improvements in pre-computed lighting resolution.