Matrix4?

Guest · Post by **Guest** » Tue Feb 10, 2004 2:18 pm

I know there is a way to grab a Matrix4 from a node, but is there a quick easy way to take a point that is not part of mesh (any point, dosnt matter) and multiply it by the Matrix4? Or would I need to write my own?

niko · Post by **niko** » Wed Feb 11, 2004 8:03 am

You mean a point outside of the mesh?

Guest · Post by **Guest** » Wed Feb 11, 2004 1:15 pm

Ok, what I was looking to do was this. I have a mesh, loaded into a Node. Now the node is transformed and rotated, for viewing purposes. In another part of my code, I am attempting to creaate a collision model from the vertices of the mesh. There fore, I read the mesh vertices into memory, and then I need to transform and rotate THOSE values into 'real' space. I was just wondering, If there was a way to pass a S3DVertex value to the Matrix4 of the Node, and have it spit out the transformed value of the point??

Guest · Post by **Guest** » Wed Feb 11, 2004 1:36 pm

I'm not sure that it's what you need but still...

There is S3DVertex::Normal vector. And there is transformVect method in matrix4. So you can do the following:

Code: Select all

S3DVertex vertex; // your vertex
ISceneNode* node; // your node

core::matrix4 mat = node->getAbsoluteTransformation(); // your matrix

// apply the same transformation to your vertex
mat.transformVect(vertex.Normal);

Do you need this or I missed something?

Guest · Post by **Guest** » Fri Feb 13, 2004 4:48 pm

Ok, I think that is what I wanted, but now how would I reverse what I did? So I can get the original point back?? Would I do this?

core::matrix4 InvertMat;
bool Inverted = mat.getInverse(InvertMat);
mat.transformVect(Point);

Or is that NOT what I want to do?? I guess I confussed why the getInverse is a bool value, how could you NOT get a matrix back??