Shapecasts not working on some areas of a mesh

Shapecasts return nil on some meshes in some cases where they should return a result. Normal raycasting returns a result in these cases.

In the repro file, the green ball represents the origin, the red is the point to shapecast to, and the blue is the result. Different CollisionFidelity settings do not work except for Box, which is not an applicable solution in my case.

The repro file only contains code for Spherecast, but Blockcasts seem to produce similar results in my game.

SpherecastRepro.rbxl (46.2 KB)

Repro steps:

  1. Open the file
  2. Run (not Play)
  3. Move the green ball around
  4. Observe that the blue ball does not always hit the surface of the mesh due to result being nil


Thanks for reporting, we’ll check this out.


Here’s my system info:

Device name DESKTOP
Processor AMD Ryzen 9 5900X 12-Core Processor 3.69 GHz
Installed RAM 32.0 GB
System type 64-bit operating system, x64-based processor
GPU AMD Radeon RX 6900 XT
Edition Windows 11 Pro
Version 22H2
Installed on ‎10/‎18/‎2022
OS build 22621.1928
Experience Windows Feature Experience Pack 1000.22644.1000.0

Roblox Studio Version 0.582.1.5820387 (64bit)

Enabled Betas:

  • New Character Controller
  • New Text Chat Service
  • Reconnect automatically to Team Create
  • Scripts Are Non-Strict By Default
  • Upgrade Shorelines
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I am also getting this bug where a Blockcast does not detect MeshParts with the CollisionFidelity of PreciseConvexDecomposition. Is there any rough ETA on when this will be fixed?

We think we have a potential fix for meshes at specific scales. This should be out in the next few releases.

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