# Physics-Based Differentiable Rendering Basics #

In this section, we cover important mathematical and algorithmic preliminaries that will be used repeatedly in the rest of the tutorials.

### Differentiating Integrals #

The differentiation of integrals plays an essential role in physics-based **differentiable rendering** since **forward rendering**—the process that needs to be differentiated—largely amounts to computing (high-dimensional) integrals.

We begin this section by discussing the differentiation of 1D and general (i.e., Lebesgue) integrals.