Once we know how each pixel is tipped, we can figure out how much light will reflect back towards the camera based on its angle. This allows us to render the lights correctly.
Before we actually use the lighting though, we need to know where the shadows are. For each light we render out a projection of each object that is in range of that light. Basically, we are drawing a blacked-out version of each object that is near the light. Based on its position and distance from the light, we distort the drawing. Just like how when you make shadow puppets, your hands look huge on the wall.
It is here that all of the lights are combined (This example only uses one light). As they are combined, the falloff for the edges of the lights are added based on the size of the light.
You might be wondering why these shadow pictures are so pixelated. That is because all of the shadow rendering is done at a much smaller resolution so that it is faster. We are going to blur the shadows later anyway, so it isn't a big deal.
Presto! The shadows and lighting are combined, and can now be used to render the final scene. You'll notice the nice blur is applied to the shadows when we do this.
Now we render the background only, with the lighting and shadows. You might be wondering why the area outside the light isn't black in this image. That is because of the ambient light. The ambient light is light that is applied evenly to everything, and prevents anything in the scene from falling into total blackness.
In the actual game, we don't render ALL of the background like this either. We actually skip rendering anything in the background that is going to be covered up by the next step, but this makes a nicer screen shot.
Lastly, the foreground elements are rendered using the lighting without the shadows to complete the scene.
Of course, we can change the colors of the lighting for something cooler:
Or something wilder:
It was important to us to take advantage of the effects possible on the Xbox 360, while at the same time keeping the painterly style of Derek's artwork. I think we ended up with a very cool aesthetic. But if you disagree, let us know! Not everything is locked in stone at this point. The normal maps, for instance, are just quick and dirty hacks right now to get something in the game. (Heck, I already rewrote the renderer since the last set of screen shots!) We've been reading the feedback from the previous batch of screenshots and changing things accordingly.
As we get farther along on the project, Derek and I are planning on spending a lot of time tweaking the lighting in the levels. We are hoping to better differentiate between levels in the same area and areas of each level. The goal is to create more moody, varied environments for the player to explore. But it also should have some real effects on game play as well. This is especially evident in the dark levels, So I thought I would end here with a little peek at one of them:
