public sealed enum Sandbox.VideoWriter.Container : System.Enum

Decodes a video file or URL and exposes the current frame as a Texture.

This section needs to be rewritten with an explanation of all the code, libraries, etc.

The "Model Editor", also known as "ModelDoc", is where you can create and edit model (VMDL) files. This is the modern equivalent of Source 1's .QC files. You can find it under the "Tools" menu.

VirtualGrid is a Panel that allows you to create a grid of items virtually. What this means is that if you have 1 million items, it won't render them and try to lay them all out at the same time. It'll just pick the few that are visible and create them. When you scroll down, it'll delete the ones it can no longer see and create the new visible ones.