On 02/07/2017 at 10:40, xxxxxxxx wrote:
Hello,
How can I transpose a matrix in C4D ? Is it possible ?
It seems that le C4D matrix are 4x4 but the first line can't be changed (always 0,0,0,1) ?
My goal is to get or calculate the normalMatrix, but not in a shader context.
Thanks
On 02/07/2017 at 12:04, xxxxxxxx wrote:
Ok, it seems that we don't care beause the first will line will be the offset matrix component :
1 0 0 0
v0.x v1.x v2.x v3.x
v0.y v1.y v2.y v3.y
v0.z v1.z v2.z v3.z
Transposed :
1 v0.x v0.y v0.z
0 v1.x v1.y v1.z
0 v2.x v2.y v2.z
0 v3.x v3.y v3.z
So with an offset v0 of (0,0,0), we will still get the first line correct.
def TransposeMatrix(m) :
v1 = Vector(m.v1.x, m.v2.x, m.v3.x)
v2 = Vector(m.v1.y, m.v2.y, m.v3.y)
v3 = Vector(m.v1.z, m.v2.z, m.v3.z)
m.v1 = v1
m.v2 = v2
m.v3 = v3
m.off = Vector()
Can you confirm me ? :-)
On 03/07/2017 at 06:44, xxxxxxxx wrote:
Hi César,
unfortunately I can only confirm that there is no function to transpose a matrix in our Python SDK.
To me, your transposed matrix in the last post looks ok.
Maybe you can tell us a bit more detail about what you are trying to achieve in the end, so we could ask our development for ideas?
Or you use something like numpy, I think Niklas once posted, that he has prepared packages for use with C4D.
On 05/07/2017 at 14:44, xxxxxxxx wrote:
Thanks for the info.
Well, it's for create a Spherical Environment UV projection, for very specific baking process.
According to the shader :
https://www.clicktorelease.com/blog/creating-spherical-environment-mapping-shader/
I needed to get the normalMatrix wich is the inverse transpose of the modelViewMatrix.
For anyone who search more infos about it :
modelViewMatrix = ~(camera.GetMg()) * op.GetMg()
normalMatrix = ~(modelViewMatrix)
TransposeMatrix(normalMatrix)
It work nice !
