Game Development Community

Matrix question

by Steve Boris · in Technical Issues · 09/08/2003 (9:41 pm) · 3 replies

I'm in the procces of making a Maya2Map plugin and have been looking at the max2map plugin to see how some things are done.

here go's

Matrix3 nodeTM = mNode->GetNodeTM(gInterface->GetTime());

Point3 maxPnt = nodeTM.PointTransform(mesh.getVert(face.v[j]));

the first code snipp basically gets the transform matrix of the current node being processed nothing hairy here.

next snip is the problem.

this code is transforming each vertice in the selected face of the current node being processed by the current node's transform matrix and returning a point3 class.

my question is: what's the difference in transforming an element in a matrix and translating an element.

Are they the Same???

I have a 10^5 documents about matrix's but all of them deal with translating them not transforming them

there is no equivalent function is Maya's matrix lib

If they are not the same how can i transform each point?

Once i understand the difference between Transforming and Translating I'll be all right.

#1
09/08/2003 (10:44 pm)
Steve,

Translating is simply moving a point along any/or its primary axis by adding/subtracting values from its x/y/z elements.

Transforming is typically used to refer to a process that can do parallel operations such as scaling, rotation *and* translation.

If you can do translation using a 4x4 homogenous matrix in MayaLib then you can encode a transformation as well. The 3x3 portion of the matrix does the scaling and rotation (as well as other operations such as shear) and the extra column/row does the transformation.

Search for "homogenous matrix" on the net to get a better understanding.

Hope this helps,

- Melv.
#2
09/09/2003 (4:49 am)
Thanks Melv
That helps alot.
#3
12/31/2003 (9:44 am)
Steve,

Did you ever finish your Maya2Map plugin?


-Joe