Roblox Studio adds tunable collisions: use Tunable without wasting performance

Primary sources: official Developer Forum announcement and Creator Hub mesh documentation.

What changes

Roblox Studio adds CollisionFidelity = Tunable for MeshPart and PartOperation. Selecting it exposes CollisionPrecision, a per-object control for balancing a more faithful collision shape against lower physics cost.

When to use it

It is especially useful when fixed options do not represent thin components, openings, or highly detailed meshes well. Maximum precision is not automatically best: more complex collision geometry also costs more.

How to test it

1. Select the problematic MeshPart.
2. In Properties, set CollisionFidelity to Tunable.
3. Adjust CollisionPrecision from Studio's automatically selected value.
4. Enable Collision fidelity in Visualization Options to compare the visible mesh with its collision shape.
5. Test the player's real route, plus moving or physics-driven objects.

Quick choice

Use Box or Hull for decoration and simple forms; try Tunable when a doorway, hole, ramp, or edge needs more fidelity; reserve PreciseConvexDecomposition for cases where measurements justify its higher cost.

Improved visualizers

Studio can display visual and collision geometry together, filter by CanCollide, CanQuery, CanTouch, and collision groups, and preview collision geometry while editing. This helps catch invisible barriers before publishing.

Important limit

Tunable does not turn collision geometry into a one-to-one copy of the visual mesh. If a complex shape still fails, Roblox recommends considering custom collision made from invisible parts, especially for large objects.

Pre-publish checklist

• [ ] Players can pass through every intended opening.
• [ ] Ramps and edges have no invisible steps.
• [ ] Decorative pieces use inexpensive fidelity.
• [ ] Collision filters match the intended interaction.
• [ ] Testing covered a place copy and a published session.