3. HDR, Lightscattering, Veggies

When we started the game some of the team were finishing off MotoGP 3 for the Xbox and the rest of us had just come off some PS2 projects. We didn’t know much about next-gen, no one did.

We had to make a lot of decisions about what technology would be important. We already had an advanced model renderer that could handle most things thrown at it – normal maps, cubic environment maps, fresnel – we had all those buzzwords covered, we also had some post-processing effects like DOF (Depth Of Field) and bloom, but now we needed to decide on the new technology that was to gel it all together.

We eventually plumped for an HDR (High Dynamic Range) renderer, light scattering and a comprehensive veggie system.

HDR Renderer
The HDR renderer allowed us to encode the intensity of a colour as well as the colour itself. So the sun, instead of just being white RGB(1,1,1) was also encoded at an intensity of 1000 to distinguish it from the white hoardings or white track markings that are much lower intensity. We used this intensity to determine when to bloom the sky or specular reflections.

We can also change the exposure value for the renderer allowing us to over or under expose a scene. This looks great in a tunnel because we’d ramp up the exposure value so as you emerged back into sunlight the scene was brightened and bloomed for a split second, before returning to normal. This simulates the expansion and contraction of the pupil.