Tools like Ninja Ripper or 3dRipper basically "intercept" the data being sent to your graphics card while the 3D viewer is running. They can grab the mesh, textures, and sometimes even the shaders. Popular tools for the job:
: Some older variations of these tools, such as 3D Ripper DX , capture geometric data directly from a computer's graphics card (DirectX 6, 8, or 9) when an application or browser viewer is running. Common "Ripping" Methods 3dcadbrowser ripper
The term "ripper" in the 3D community refers to a script, browser extension, or standalone software designed to bypass a website’s front-end restrictions to download 3D models that are not meant to be saved locally. Tools like Ninja Ripper or 3dRipper basically "intercept"