Exoide

01-25-2010, 05:53 PM

Hi there,

I need to get the inverse matrix of the model-view matrix.

To do it faster can I do it in the following way:

1- Multiply by (-1) the translation vector in the matrix (only X, Y, Z items of the vector)

2- Calculate the transpose of the 3x3 sub matrix that contains the rotation vectors

3- Update the first three items of the diagonal with this 1/m11, 1/m22, 1/m33

Of course that method is only valid for the following transformations:

1- Translation

2- Rotation

3- Scale

Can I calculate the inverse in that way? I mean, is this an accurate way to get the inverse?

Thank you.

PD: I will only do these transformations in the model-view.

I need to get the inverse matrix of the model-view matrix.

To do it faster can I do it in the following way:

1- Multiply by (-1) the translation vector in the matrix (only X, Y, Z items of the vector)

2- Calculate the transpose of the 3x3 sub matrix that contains the rotation vectors

3- Update the first three items of the diagonal with this 1/m11, 1/m22, 1/m33

Of course that method is only valid for the following transformations:

1- Translation

2- Rotation

3- Scale

Can I calculate the inverse in that way? I mean, is this an accurate way to get the inverse?

Thank you.

PD: I will only do these transformations in the model-view.