If you are using the (optional, non-default) Inner Box avatar collision game option, we’re making some changes to the way we size and position these boxes that may affect your game.
This change won’t affect you if you’re using the default Avatar collisions, Outer Box, and we encourage you to continue using it!
How to Check Your Collision Settings
If you might have changed this setting within the past year you may want to double check which one you are using. For the past year the labels were accidentally flipped by a localization change, and this was only recently fixed. You might not be using the one you thought you were!
Note: We recommend using Outer Box unless you have a specific problem in your game that Inner Box actually fixes.
What is Inner Box?
The slightly misleadingly named Inner Box collision mode attempts to size the collision boxes of an avatar identically to a classic R15.
This is done by applying artificial
CollisionFidelity.Hull collisions to the MeshParts, using potentially differently sized and offset boxes relative to the actual part. This box may be larger or smaller than the original part.
This does come at a small cost:
- There is a small performance cost when these parts collide with other parts. Hull collisions use a slightly more expensive collision test than our standard box collisions.
- It takes the server an extra ~0.5 ms to apply inner box collisions when a character spawns.
- Sending the extra collision data for each avatar part may increase join times marginally.
- This introduces more of a physical-visual disconnect for avatar collisions.
We’re changing the the sizing and positioning algorithm for Inner Box slightly.
The current algorithm just simply copies the R15 box sizes, using an offset based on the average position of all Attachments, including the accessory mount attachments. This offset method doesn’t consistently respect the positions of the joints. When this is applied to the same classic R15 it is attempting to normalize to, it produces different offsets and introduces gaps!
The new algorithm 9-slices (actually 14-slices, since it’s 3d) the collision boxes around the avatar’s joint RigAttachments, and applies the part size margins around the RigAttachments from a classic R15 to the extents of the RigAttachments on the new part.
This generates better fit Classic R15 “style” collision boxes that better respect the positioning of the joints, more appropriately sized for wider, narrower, longer, or shorter parts, while providing the same collision size “normalization” benefits.
Note the better positioning of the hands and feet in the comparison below. “Rig Extents Margin Inner Box” is the new algorithm.
Also when applied to a classic R15 this produces identical results to the reference parts, and does not introduce unintentional gaps like the current Inner Box algorithm.
When is it Changing?
We’ll be enabling this change for all games next week on Thursday, June 3rd.
If you want to test this yourself it’s available now as a Studio Beta Feature: