Animated gif demonstrates adding specular shine to shadows in new FUEL shaders... and the inaccuracy of it. Light bounces off things in real life, and ends up back in shadows to a) overall light up shadows (otherwise they'd be pitch black), b) reflect off surfaces in the shadows to create shiny and dull spots on things. We simulate that by allowing a bit of specular to process in shadows. But, as you can see with the building compared to the metal panel on the ground, the specular is not completely realistically accurate. The building is cut-off on specular, looking flat. The specular is taking the lighting angle and just dulling it down in shadows, so in some situations it looks like light penetrating through a solid object that would otherwise block or dull the speculars. This is where better Ambient Occlusion would help in the game.. where corners and edges (like the one running along where the building meets the metal panel) would AO and darken / block more light to add more body and depth to the scene. FUEL has pretty simply AO. I looked into adding more complex AO algorithms to the game that would do edge AO and such, but it would require messing with the game engine to process things. So, you do the best you can with what you have.
Animated gif demonstrates adding specular shine to shadows in new FUEL shaders... and the inaccuracy of it. Light bounces off things in real life, and ends up back in shadows to a) overall light up shadows (otherwise they'd be pitch black), b) reflect off surfaces in the shadows to create shiny and dull spots on things. We simulate that by allowing a bit of specular to process in shadows. But, as you can see with the building compared to the metal panel on the ground, the specular is not completely realistically accurate. The building is cut-off on specular, looking flat. The specular is taking the lighting angle and just dulling it down in shadows, so in some situations it looks like light penetrating through a solid object that would otherwise block or dull the speculars. This is where better Ambient Occlusion would help in the game.. where corners and edges (like the one running along where the building meets the metal panel) would AO and darken / block more light to add more body and depth to the scene. FUEL has pretty simply AO. I looked into adding more complex AO algorithms to the game that would do edge AO and such, but it would require messing with the game engine to process things. So, you do the best you can with what you have.