Box Cut out Shader function

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1

I am trying to create a Custom function to be used in Shader Graph that cuts out a box on an object.
I want to be able to feed in the World coordinates of a cube to the function and it to return a value float and connect it to the alpha channel.

So far i have this:

void  IsVertexInsideBox_float(float3 vertexPosition, float3 boxPosition, float3 boxScale, float4 boxRotation, float4 objectWorldRotation , out float Out)
{
    float4x4 rotationMatrix = quaternion_to_matrix(boxRotation);
    // Transform the point into the local space of the cube
    float3 localPoint = mul(rotationMatrix, vertexPosition - boxPosition) / boxScale;

    // Check if the transformed point is within the cube
    bool insideCube = abs(localPoint.x) <= 0.5 && abs(localPoint.y) <= 0.5 && abs(localPoint.z) <= 0.5;

    Out =  insideCube ? 1 : 0;
}

At first it seems like it works fine, i can move the box and rotate its Y axis and all looks good.

But if i rotate other axis or the “shaded” object it all goes wrong from there… :frowning:

Any tips, links or solution on how to solve this?

Thanks in advance!!

Looks good,

image
image759Ă—561 11.8 KB

Sad life

image (2)
image (2)775Ă—591 20.4 KB

2

Well, what is this boxRotation? Is it the local2World or the world2Local rotation? That said, wouldn’t it make more sense to just provide the whole transform matrix instead of a position, rotation and scale manually? I mean that’s why we have matrices in the first place :slight_smile:

So what exactly do you pass as boxRotation? The box’s rotation quaternion or the inverse of that?