*On 14/01/2015 at 08:08, ***xxxxxxxx** wrote:

**Originally posted by xxxxxxxx**

Hello,

you can invert a Matrix with "__invert__()" or the Python "invert" operator "~" .

```
inverseMatrix = ~worldSpaceCoords
```

You may also take a look at the GeRayCollider that can be used to calculate the intersections of a ray and a poly object.

best wishes,

Sebastian

Yes, but that is all for a cinema 4d matrix and that is a 4x4 matrix, not a 3x3 matrix.

I want to use a 3x3 matrix.

I know I can use the GeRayCollider, but I want to do it myself.

So, how to do 3x3 matrix calculations in cinema 4d?

-Pim