transform.InverseTransformDirection For ECS

Hi,

Can someone Tell me how to use the equivalent of transform.InverseTransformDirection for ECS ?
Knowing i have no access to the Transform Component within a ComponentSystem.
Thank you.

 

You have to access LocalToWorld component and manipulate its matrix directly (float4x4)

 

I know but what's the logic behind transform.InverseTransformDirection.
This is what I'm asking.

 

Yes please, I'm stuck with this too. Would be nice if the unity.mathematics had some of the most common Transform math inside it.

 

I haven't tested or really looked in, but I'd assume you'd just inverse your LocalToWorld matrix (math.inverse) to make a WorldToLocal matrix and use that.

 

Code (CSharp):

1.         public void Execute([ReadOnly] ref Velocity V, ref LocalVelocity LocalVelocity, [ReadOnly] ref Rotation Rotation, [ReadOnly] ref LocalToWorld LtW)
2.         {
3.             float3 l = math.mul(Rotation.Value, V.Value);
4.             LocalVelocity.Value = new float3(l.x, l.y, l.z);
5.         }

This is what I'm trying to do. I have an animation system that needs the animators local velocity in order to find the right pose.
This works for when the direction is forward or back, but doesnt work when the object is facing right or left.
Any tips?

 

if you want to use Transforms Functions like normal GO workflow, the Matrix4x4 contains many of them. (more infos here).

you need to get the LocalToWorld ComponentData and use it to create a Matrix4x4.

if you dont want to use the LocalToWorld ComponentData, you can create it using Translation, Rotation, Scale.
Matrix4x4 matrix4x4 = Matrix4x4.identity;
matrix4x4 .SetTRS(translation, Rotation, Scale);



// Direction Functions
//Matrix4x4 version of Transform.InverseTransformDirection
Vector3 localDirection = matrix4x4.inverse.MultiplyVector(worldDirection);

//Matrix4x4 version of Transform.TransformDirection
Vector3 worldDirection = matrix4x4.MultiplyVector(localDirectionDirection);


// Position Functions
//Matrix4x4 version of Transform.InverseTransformPoint
Vector3 localPosition = matrix4x4.inverse.MultiplyPoint3x4(worldPositon);

// Matrix4x4 version of Transform.TransformPoint
Vector3 worldPositon = matrix4x4.MultiplyPoint3x4(localPosition );

Matrix4x4 is a struct so you can use all this inside jobs

 

Enormous thanks, Ill look into this

EDIT: It works!

 

in case someone still confusing:

Code (CSharp):

1. // InverseTransformPoint equivalent:
2. math.transform(math.inverse(SomeLocalToWorld), WorldPostion)

 

to get GO api: transform.TransformDirection() in ECS

Code (CSharp):

1.  
2.         public static float3 LocalToWorld(this float4x4 localtoworld_Component, float3 direction)
3.         {
4.             return math.rotate(localtoworld_Component, direction);
5.         }

 

If you are on ECS 1.0 and using transforms v2, you can use LocalTransform.TransformDirection(), WorldTransform.TransformDirection() or the various methods available on the TransformAspect.