Roblox pivot offset: why props float, sink or spin wrong

What Roblox expects

A MeshPart positions and rotates around its CFrame origin, the pivot. The convention for placeable props is bottom-center: the pivot rests on the floor plane, with the mesh centered on X and Z. Drop-to-surface, align tools and rotations then behave predictably, because the origin is where the prop touches the world.

Most 3D tools do not export that way. Blender's object origin sits wherever it was last left, often at the bounding-box center or at some leftover edit position. The offset gets baked into the vertex data and travels with the mesh into Studio.

Three ways to fix it

1. 1.In Studio, by hand. Select the model, use Home → Pivot → Edit Pivot, and drag the origin to the bottom-center of the mesh. Fine for one prop, slow for a library of them.
2. 2.In Blender, before export. Snap the mesh so its lowest face rests on Z = 0 and it is centered on X/Y. Set the 3D cursor to that point (Shift+C first to reset), then Object → Set Origin → Origin to 3D Cursor. Apply all transforms (Ctrl+A) and export.
3. 3.Automatically. The Pivot Wizard takes any GLB or OBJ, rebuilds it with a bottom-center pivot, model resting on the floor and centered on X/Z, and hands back a Studio-ready ZIP. First fix free.

How to verify a pivot in ten seconds

The Mesh Checker reports where the mesh base sits. If it says the base is at Y = -1.43 studs, the prop will sink 1.43 studs into the ground the moment you place it at floor level. X/Z centering is checked the same way.