if you want to do it the hard way you can do it like this:
# Python
import math
x = -45.0
y = 45.0
z = 0.0
def degToRad(value):
return value * (math.pi / 180)
cx = math.cos(degToRad(x))
sx = math.sin(degToRad(x))
cy = math.cos(degToRad(y))
sy = math.sin(degToRad(y))
cz = math.cos(degToRad(z))
sz = math.sin(degToRad(z))
rotationX = XSIMath.CreateMatrix3( 1,0,0,
0,cx,sx,
0,-sx,cx)
rotationY = XSIMath.CreateMatrix3( cy,0,-sy,
0,1,0,
sy,0,cy)
rotationZ = XSIMath.CreateMatrix3( cz,sz,0,
-sz,cz,0,
0,0,1)
rotationXY = XSIMath.CreateMatrix3( rotationX.Value(0,0) *
rotationY.Value(0,0) + rotationX.Value(0,1) * rotationY.Value(1,0) +
rotationX.Value(0,2) * rotationY.Value(2,0),
rotationX.Value(0,0) * rotationY.Value(0,1) + rotationX.Value(0,1) *
rotationY.Value(1,1) + rotationX.Value(0,2) * rotationY.Value(2,1),
rotationX.Value(0,0) * rotationY.Value(0,2) + rotationX.Value(0,1) *
rotationY.Value(1,2) + rotationX.Value(0,2) * rotationY.Value(2,2),
rotationX.Value(1,0) * rotationY.Value(0,0) + rotationX.Value(1,1) *
rotationY.Value(1,0) + rotationX.Value(1,2) * rotationY.Value(2,0),
rotationX.Value(1,0) * rotationY.Value(0,1) + rotationX.Value(1,1) *
rotationY.Value(1,1) + rotationX.Value(1,2) * rotationY.Value(2,1),
rotationX.Value(1,0) * rotationY.Value(0,2) + rotationX.Value(1,1) *
rotationY.Value(1,2) + rotationX.Value(1,2) * rotationY.Value(2,2),
rotationX.Value(2,0) * rotationY.Value(0,0) + rotationX.Value(2,1) *
rotationY.Value(1,0) + rotationX.Value(2,2) * rotationY.Value(2,0),
rotationX.Value(2,0) * rotationY.Value(0,1) + rotationX.Value(2,1) *
rotationY.Value(1,1) + rotationX.Value(2,2) * rotationY.Value(2,1),
rotationX.Value(2,0) * rotationY.Value(0,2) + rotationX.Value(2,1) *
rotationY.Value(1,2) + rotationX.Value(2,2) * rotationY.Value(2,2))
rotationXYZ = XSIMath.CreateMatrix3(rotationXY.Value(0,0) *
rotationZ.Value(0,0) + rotationXY.Value(0,1) * rotationZ.Value(1,0) +
rotationXY.Value(0,2) * rotationZ.Value(2,0),
rotationXY.Value(0,0) * rotationZ.Value(0,1) + rotationXY.Value(0,1) *
rotationZ.Value(1,1) + rotationXY.Value(0,2) * rotationZ.Value(2,1),
rotationXY.Value(0,0) * rotationZ.Value(0,2) + rotationXY.Value(0,1) *
rotationZ.Value(1,2) + rotationXY.Value(0,2) * rotationZ.Value(2,2),
rotationXY.Value(1,0) * rotationZ.Value(0,0) + rotationXY.Value(1,1) *
rotationZ.Value(1,0) + rotationXY.Value(1,2) * rotationZ.Value(2,0),
rotationXY.Value(1,0) * rotationZ.Value(0,1) + rotationXY.Value(1,1) *
rotationZ.Value(1,1) + rotationXY.Value(1,2) * rotationZ.Value(2,1),
rotationXY.Value(1,0) * rotationZ.Value(0,2) + rotationXY.Value(1,1) *
rotationZ.Value(1,2) + rotationXY.Value(1,2) * rotationZ.Value(2,2),
rotationXY.Value(2,0) * rotationZ.Value(0,0) + rotationXY.Value(2,1) *
rotationZ.Value(1,0) + rotationXY.Value(2,2) * rotationZ.Value(2,0),
rotationXY.Value(2,0) * rotationZ.Value(0,1) + rotationXY.Value(2,1) *
rotationZ.Value(1,1) + rotationXY.Value(2,2) * rotationZ.Value(2,1),
rotationXY.Value(2,0) * rotationZ.Value(0,2) + rotationXY.Value(2,1) *
rotationZ.Value(1,2) + rotationXY.Value(2,2) * rotationZ.Value(2,2))
xfo = XSIMath.CreateTransform()
xfo.SetRotationFromMatrix3(rotationXYZ)
Application.Selection(0).Kinematics.Global.PutTransform2(None, xfo)
On Mon, Aug 26, 2013 at 6:05 PM, Matt Lind <[email protected]> wrote:
> Don't you have Mr LaForge and Mr. LeClaire at your disposal? I would
> think they could answer in a heartbeat.
>
>
> Anyway, an alternate way of dealing with this problem is to export the
> axis vectors instead of computing the rotations. This ensures you get a
> match and you don't have to deal with math.
>
>
> Matt
>
>
>
>
> -----Original Message-----
> From: [email protected] [mailto:
> [email protected]] On Behalf Of Eric Thivierge
> Sent: Monday, August 26, 2013 2:46 PM
> To: [email protected]
> Subject: SI Matrix3 and Maths
>
> Hey all,
>
> Plunging ever further into the depths of matrices and the fun math issues
> one may need to solve while building some tools for the studio.
>
> I'm trying to figure out how the SI Matrix3's are derived / set and am
> hitting some walls. I have some Euler angles that I need to convert to
> Matrix3's then set a Transform from the result.
>
> Basically a Euler angle to Matrix3 operation. I need to solve this without
> the built in methods as I need to convert data from external sources to
> align with Softimage without the SDK available.
>
> I've referenced many of web sites (wikipedia, educational institutions,
> etc.) and all of the equations for multiplying the 3 matrices (x,y,z) end
> up with results that are not consistent with Softimage's methods.
> The only source that has proven to give me valid results is the 3D Math
> Primer for Graphics and Game Dev book (Chapter 8.7). However it only shows
> the solution for XYZ rotation order and even that I'm unsure how they got
> the order in which they multiply the rows / columns.
>
> If any of you smart people out there (Raf, Matt?) have a few free minutes
> to review my below code and show me the error of my ways I'd appreciate it.
> Maybe others could benefit too.
>
> Create 2 nulls. Set one rotation to x = -45, y=45 Select 2nd null and run
> script.
> Swap the commented "result" line and run again.
>
> # Python
> import math
>
> si = Application
> log = si.LogMessage
> sel = si.Selection
>
> def degToRad(value):
> return value * (math.pi / 180)
>
> x = -45
> y = 45
> z = 0
>
>
> cx = math.cos(degToRad(x))
> sx = math.sin(degToRad(x))
> cy = math.cos(degToRad(y))
> sy = math.sin(degToRad(y))
> cz = math.cos(degToRad(z))
> sz = math.sin(degToRad(z))
>
>
> matX = XSIMath.CreateMatrix3()
> matX.Set(0,1,0,0,cx,sx,0,-sx,cx)
>
> matY = XSIMath.CreateMatrix3()
> matY.Set(cy,0,-sy,0,1,0,sy,0,cy)
>
> matZ = XSIMath.CreateMatrix3()
> matZ.Set(cz,sz,0,-sz,cz,0,0,0,1)
>
> result = XSIMath.CreateMatrix3()
> # From most sites I referenced-ish
> #result.Set(cz*cy, sz*cx + cz*sy*sx, sz*sx - cz*sy*cx, -sz*cy, cz*cx -
> sz*sy*sx, cz*sx + sz*sy*cx, sy, -cy*sx, cy*cx)
>
> result.Set(cy*cz + sy*sx*sz, sz*cx, -sy*cz + cy*sx*sz, -cy*sz + sy*sx*cz,
> cz*cx, sz*sy + cy*sx*cz, sy*cx, -sx, cy*cx) # From Book
>
> log(result.Get2())
>
> xfo = XSIMath.CreateTransform()
> xfo.SetRotationFromMatrix3(result)
>
> sel(0).Kinematics.Global.PutTransform2(None, xfo)
>
> # End Python
>
> --
>
> Eric Thivierge
> ===============
> Character TD / RnD
> Hybride Technologies
>
>
>
>
>
