CSG toMesh material required

[brianzinn]

https://github.com/BabylonJS/Babylon.js/blob/c319ca1cbfa1b249bee93771d4fea1d4279f5e25/src/Mesh/babylon.csg.ts#L590

I think the signature should be:
public toMesh(name: string, material: Nullable<Material>, scene: Scene, keepSubMeshes: boolean): Mesh {

I can PR if you want and that is correct.  thanks.

[GameMonetize]

I will fix it

thanks!

[brianzinn]

@Deltakosh Thanks - whole game builds with strictNullChecks compile option enabled!

One gotcha is that there are a lot of Nullable<T> (Nullable<T> = T | null), while they can often be undefined.  ie: mesh.physicsImpostor.  Not sure if it makes sense to default some to null - or at least new Nullable<T> properties that are added in the future.

ie: https://github.com/BabylonJS/Babylon.js/blob/master/src/Mesh/babylon.abstractMesh.ts#L357

Could be

public physicsImpostor: Nullable<PhysicsImpostor> = null;

So, right now I need to check if (mesh.physicsImpostor) {...}, whereas I thought I could do if (mesh.physicsImpostor !== null) {..}.  I have a feeling that would break a lot of existing code, so I would guess it is just something we have to deal with knowing how it is implemented  

[GameMonetize]

I'm ok with that  feel free to send tiny PR for that !

[brianzinn]

I tested it out and created a PR: https://github.com/BabylonJS/Babylon.js/pull/3382

[brianzinn]

Those 2 fields are really the tip of the iceberg.  Before even if I checked "if (mesh.physicsImpostor !== undefined)", I would get a potential Null warning in compiler in my if block, while checking for not null did not work and failed at runtime (default was undefined).  I think it's hard to say a (T | null) can either be a T or null only, which is what we expect from a typed language and not so much from JavaScript, but it does add some consistency and match the .d.ts file to help people in their editors and compile/lint errors.  Cheers.