Wannathis - 3d illustrations and freebies
Spline - Design tool for 3d web experiences
LostGeometry.xyz - Huge set of 91 abstract 3D objects in various styles.
Webflow 3D Transforms - Build 3D interactions visually, without writing any code
Craftwork - A collection of User Interface resources made by Craftwork
Vectary - Vectary is a free, online 3D modeling tool and sharing platform.