Exploring the ray marcher

Now that we have the color and density values for all the points sampled with the ray sampler, we need to figure out how to use it to finally render the pixel value on the projected image. In this section, we are going to discuss the process of converting the densities and colors on points of rays to RGB values on images. This process models the physical process of image formation.

In this section, we discuss a very simple model, where the RGB value of each image pixel is a weighted sum of the colors on the points of the corresponding ray. If we consider the densities as probabilities of occupancy or opacity, then the incident light intensity at each point of the ray is a = product of (1-p_i), where p_i are the densities. Given the probability that this point is occupied by a certain object is p_i, the expected light intensity reflected from this point is w_i = a p_i. We just use w_i as the weights for the weighted sum of colors. Usually, we normalize...