4. Rendering Mike Wazowski

- In the first few videos, we discussed the basic job of a ray tracer: determine the final pixel color for each pixel in an image. Let's look at a "real-world" example from Monster's University. First, for each pixel, we need to find the intersection point between a ray, starting at the camera, shooting through a pixel, and shooting into the scene. The next step is to ask, "What color is each of these surfaces?" It turns out that color, alone isn't very interesting to look at, right? Next, we need to determine how the surface will respond to light. As we discussed earlier, the two basic components of surface response are called diffuse and specular. This is a picture of how diffuse, or dull, each object is. Where this image is bright white is gonna be where the dullest surface in the scene is. For example, the hat is really dull. And this is a picture of how specular, or shiny, each object is. Now, from this image, can you tell where the main light source is? Pause the video now, if you need some more time. The light source is off to the left side of the screen. You can actually see it reflected in Mike's eye, here. Now, each object in the scene receives directing lighting, which we see here in these images of diffuse and specular. But they also received indirect lighting, which is light bouncing off of other objects in the scene. So what happens when we put all these calculations together? It's kind of magical, right? That's what we do. It's math, but used to create magic!