What are you attempting to achieve? - I’m trying to make a secret room in the dirt
What is the issue? - When ever I try to clear a room out, I can’t walk through it
(The white ring was just for testing)
I’ve made other stuff before with unions and there wasn’t any collision so can anyone help me out?
your solution is the search bar
Collision fidelity. You need to set it to precise on the union
As @ScrollFrameRotation said, it’s been solved before. Basically you’re taking a very small percentage of the area away from the union so it doesn’t actually remove it.
In a case like this you may be best to use a large CanCollide false Part as your grass, and 4 CanCollide true Parts to create your hole that are about .010 studs below the surface of the grass Part.
Maybe I think broken collision fidelity algorithm , should be better using PreciseConvexDescomposition
I’m a bit confused about what you mean. Are you referring to how using a negative part that is flush with the positive parts can create a super-thin collision layer?
I meant to have a CanCollide false part for the grass, then put 4 CanCollide true transparent Parts to create a baseplate with a very definite hole in it. You could make them opaque as well, they’d just have to be slightly below the surface of the grass so they wouldn’t show.
For the percentage part of my explanation:
Take a part that’s 200 studs by 200 studs.
Negate a 5x5 stud hole in the middle of it.
200x200 studs is 40,000 square studs.
5x5 studs is 25 square studs.
25 / 40,000 = .000625, which means that your hole is only .0625% of the entire Union. It seems like Unions of large parts with small holes works on a percentage system.
If you took a 20 x 20 stud Part (400 square studs) and negated a 5 x 5 stud hole out of it that would be a 6.25% hole in the Union and would probably be a very close fit to the actual hole size if you used PreciseConvexDecomposition.
There’s a cool tool in your Studio settings that allows you to see the physical shape of Unions and MeshParts in each of the CollisionFidelities you can choose.
File > Studio Settings > Physics > ShowDecompositionGeometry. Click it and you’ll see Unions and MeshParts as coloured shapes. If you choose the different CollisionFidelities you’ll see the shape change which shows what the item is actually shaped as. I’m guessing if you did this with your original Union it’d show as a complete block with either no hole or a very small odd shaped hole in it.
Just go to the union go to Collision fidelity in properties and click PreciseConvexDescomposition
Omg I didn’t even see that, thanks guys and sorry for wasting your time 