Shapecast vs Raycast performance differences?

[TheCreatorBenn (benn)]

Can someone tell me the cost of a shapecast relative to a raycast? How many raycasts would it take to be less beneficial to performance compared to a shapecast? Is there any resources on how roblox makes the shapecasts work?

Introducing Shapecasts

Today we’re officially releasing two new APIs for the Roblox Engine: WorldRoot:Blockcast WorldRoot:Spherecast You may know these as swept volume queries, thick raycasts, continuous collision detection, or various other names across the industry. We call them Shapecasts. [image] Shapecasts are closely related to raycasts – Raycasts push a point along a line, while shapecasts push a 3D shape and find the first hit point. Use cases Some examples of when you might find these useful: Chara…

[OfficialPogCat (POG_Cat)]

@TheCreatorBenn

How many raycasts would it take to be less beneficial to performance compared to a shapecast?

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@subcritical

Performance

Performance is close to a raycast for a 0,0,0 size shapecast, with some exceptions caused by differences in how we traverse 3D space. This is because a 0,0,0 size shapecast is roughly equivalent to a raycast.

From there, performance degrades according to the size of the shape and the length of the cast.

and

@subcritical

Secondly, for performance reasons, we impose limitations on size and length:

• Maximum ray length: 1024 studs
• Maximum shape size: 512 studs

Passing a shape that’s too big or a ray that’s too long will give you an error message with the current length limitations. We plan to raise both of these numbers over time as we improve the performance of the shapecast internals.

I personally haven’t used the new Shapecast too much. But hopefully this helps a little?

[TheCreatorBenn (benn)]

I’ve seen that in the post, but it doesn’t really answer my question since it doesn’t give any perspectives on the relative cost. For instance if a shapecast of 1 studs thick. I wouldn’t have any estimate of that cost compared to how many raycasts. If both ray and shape casts are the same length and the shape cast is 1 stud thick and lets say it’d equivalent to 10 raycasts then I can use that as a unit of measure for the cost.