Retopologizing

Retopologizing is a fundamental process in 3D computer graphics used to create a new, optimized polygonal mesh over an existing high-resolution mesh. This new mesh, often referred to as the "low-poly" or "retopologized" mesh, has a significantly reduced polygon count compared to the original. The primary purpose of retopologizing is to improve performance and efficiency for various downstream applications.

High-resolution models, often generated through sculpting software or 3D scanning, can contain millions of polygons. While this provides incredible detail, it makes the model unwieldy for real-time rendering in video games, animation, or interactive applications. The high polygon count can lead to slow frame rates, increased memory usage, and difficulty in rigging and animation.

The retopology process involves manually or semi-automatically drawing new polygons onto the surface of the high-resolution model. The goal is to capture the essential shape and silhouette of the original model with a much simpler and cleaner edge flow. Good edge flow is crucial as it guides the deformation of the mesh during animation and helps in baking details from the high-poly model onto the low-poly version.

Once the low-poly mesh is created, its surface details are typically transferred from the high-resolution model using a process called normal mapping or other baking techniques. This allows the low-poly model to appear as detailed as the high-poly original in rendering, while maintaining performance benefits. Retopologizing is an essential step in the character modeling, game asset creation, and asset optimization pipelines.