CALLING ALL MATRIX GURUS, HELP! , please :)

MarcioAB

The 16-elements matrix you show up, have Origin, Axis, Scale data relative to a parent coordinate system (can be the Global system but can also be the coordinate system of it's parent component).

The first line has the x,y,z projections (in the parent's coordinate system) of vector X of the axis. Then the scale in this direction.
The same for the other 2 lines regard vector Y and Z of the axis.
The last line has the axis' coordinates x,y,z (in the parent's coordinate system). And the last number is the overall scale.

You can create a TRANSFORMATION directly with this 16-elements matrix and apply it to an object that accepts transformation method, BUT ... Camera does not accept transformation method.

Instead, Camera has it's own "transformation" method that is called SET. The SET method is based on:

Target: a 3Dpoint where the Camera is looking for.
Eye: a 3Dpoint where the Camera is.
Top: a 3Dvector indicating the rotation of the camera regard the direction Eye-Target. Normally it's the Z-direction, to make the camera stand up.

This is what the "on-line" manual says for Camera Class
Please take a look in CameraOOT

Regards
Marcio

MarcioAB

2nd thought ... based on your data:

target => 3Dpoint of [0.999938,0.001129,-0.011103]
eye => 3Dpoint of [1.054297,1.571880,-8.966838]
up => 3Dvector of [-0.011108,0.005189,-0.999925]

Can not test because not have a working system here ...

Regards
Marcio

jessejames

Many thanks my friend, I had almost given up hope.

I am 99% sure this is referring to world coordinates.I will try your suggestions and post back if this does not work. Stay tuned

jessejames

OK, i tried the suggestion...


target => 3Dpoint of [0.999938,0.001129,-0.011103]
eye => 3Dpoint of [1.054297,1.571880,-8.966838]
up => 3Dvector of [-0.011108,0.005189,-0.999925]

but it is not correct, i will continue to play around with the values to see if i can fiqure this out. If you have any more thoughts feel free to post them.
Thanks

Jim

It is hard to know what the matrix values mean. You say they are from a source outside of SketchUp, but what application? If you are exporting coordinates from another program, make the position of the exported object more extreme so you can see some values in the matrix that are extreme.

jessejames

OK Guys,
The program i am getting this data from is Blender via a python script.

I have some information that may help you to help me . I created a new camera in Blender and played with the rotation a bit. here is an output from that session. Note: that after each Rotation i reset the camera to it's original position. So first i rotated 90deg on X axis, printed the matrix, then i reset the camera... and so on.

I applied some rotations and deduced the following data(eye,target,up) by looking at the actual camera. my visual data is between the "<" and ">" . Luckily in Blender the camera is actually visible.

<camera at Loc(0,0,0). target(0,0,-1), up(0,1,0)>
[1.000000, 0.000000, 0.000000, 0.000000]
[0.000000, 1.000000, 0.000000, 0.000000]
[0.000000, 0.000000, 1.000000, 0.000000]
[0.000000, 0.000000, 0.000000, 1.000000]

after RotX += 90
<Loc(0,0,0) target(0,1,0) up(0,0,-1)>
[1.000000, 0.000000, 0.000000, 0.000000]
[0.000000, -0.000000, 1.000000, 0.000000]
[0.000000, -1.000000, -0.000000, 0.000000]
[0.000000, 0.000000, 0.000000, 1.000000]
#reset camera

after RotY += 90
<Loc(0,0,0) target(-1,0,0) up(0,1,0)>
[-0.000000, 0.000000, 1.000000, 0.000000]
[-0.000000, 1.000000, -0.000000, 0.000000]
[-1.000000, -0.000000, -0.000000, 0.000000]
[0.000000, 0.000000, 0.000000, 1.000000]
#reset camera

after RotZ += 90
<Loc(0,0,0) target(0,0,-1) up(-1,0,0)>
[-0.000000, 1.000000, 0.000000, 0.000000]
[-1.000000, -0.000000, 0.000000, 0.000000]
[0.000000, -0.000000, 1.000000, 0.000000]
[0.000000, 0.000000, 0.000000, 1.000000]

Maybe from this data some one can figure out the matrix? It still does not make any sense, i cannot find the values within the matrix in a form that makes any sense??

If you can make anything of this data i will give you a big kiss, tongue, no tongue your choice . I really need to figure out the target(point) and up(vector) so i can use this data in SU. the eye is M[-1] i know that already. Thanks so much for any help you can give.

Pixero

I've written a MentalRay shader that has many different matrixes like scale, transform, shear, scale, rotation order and more.
You can download the zip with the source code and take a look.
Hope this helps.

http://www.pixero.com/files/JS_Place3dTexture.zip

jessejames

Thanks Pixero,
I will look into this right now.

jzer7

Not a matrix person, but my 2 cents... From Indigo's exporter in the Blender wiki (look for "Process Camera", it looks like:


up = matrix[1]
forwards = matrix[2]
pos = matrix[3]

So, up should be the second row, forwards the third and pos the fourth.

Good luck

Juan

jessejames

jzer7,
Thanks so much, but no luck.

I going to post a section of the script i am parsing this data from, maybe it will help...



import Blender
from Blender import Camera, Object, Scene, NMesh
from Blender import Mathutils
from Blender.Mathutils import *
cur = Scene.getCurrent()

#Camera Parameters
c0001 = Camera.New('persp')
c0001.lens = 49.739047
o0001 = Object.New('Camera')
o0001.name = "voodoo_cam1"
o0001.setMatrix(Mathutils.Matrix([0.999938,0.001129,-0.011103,0.000000], [0.001072,-0.999986,-0.005202,0.000000], [-0.011108,0.005189,-0.999925,0.000000], [1.054297,1.571880,-8.966838,1.000000])) 
o0001.link(c0001)
cur.link(o0001)

c0002 = Camera.New('persp')
c0002.lens = 49.739047
o0002 = Object.New('Camera')
o0002.name = "voodoo_cam2"
o0002.setMatrix(Mathutils.Matrix([0.999943,0.001132,-0.010635,0.000000], [0.001076,-0.999985,-0.005294,0.000000], [-0.010641,0.005282,-0.999929,0.000000], [1.071295,1.559580,-8.822482,1.000000])) 
o0002.link(c0002)
cur.link(o0002)


##################################################
# [snip]
# many, many more cams are created and then comes 
# some IPO curve data
#################################################


#Render camera animated with IpoCurves
crender = Camera.New('persp')
crender.lens = 35.0
crender.setDrawSize(1.0)
orender = Object.New('Camera')
orender.name = "voodoo_render_cam"
orender.link(crender)
cur.link(orender)
cur.setCurrentCamera(orender)
ipo = Blender.Ipo.New('Object','render_cam_objipo')
orender.setIpo(ipo)
locx = ipo.addCurve('LocX')
locx.setInterpolation('Linear')
locy = ipo.addCurve('LocY')
locy.setInterpolation('Linear')
locz = ipo.addCurve('LocZ')
locz.setInterpolation('Linear')
rotx = ipo.addCurve('RotX')
rotx.setInterpolation('Linear')
roty = ipo.addCurve('RotY')
roty.setInterpolation('Linear')
rotz = ipo.addCurve('RotZ')
rotz.setInterpolation('Linear')
camipo = Blender.Ipo.New('Camera','render_cam_camipo')
crender.setIpo(camipo)
lenscurve = camipo.addCurve('Lens')
lenscurve.setInterpolation('Linear')

locx.addBezier((1,o0001.LocX))
locy.addBezier((1,o0001.LocY))
locz.addBezier((1,o0001.LocZ))
rotx.addBezier((1,o0001.RotX*18/3.141593))
roty.addBezier((1,o0001.RotY*18/3.141593))
rotz.addBezier((1,o0001.RotZ*18/3.141593))
lenscurve.addBezier((1,c0001.lens))

locx.addBezier((2,o0002.LocX))
locy.addBezier((2,o0002.LocY))
locz.addBezier((2,o0002.LocZ))
rotx.addBezier((2,o0002.RotX*18/3.141593))
roty.addBezier((2,o0002.RotY*18/3.141593))
rotz.addBezier((2,o0002.RotZ*18/3.141593))
lenscurve.addBezier((2,c0002.lens))

############################################
# [snip]
# many more lines of IPO
# the only thing left is "point cloud" data 
# which i am leaving out. 
# The last thing in the script is this...
###########################################

# Scene Helper Object
scene_dummy= Object.New('Empty','voodoo_scene')
scene_dummy.setLocation(0.0,0.0,0.0) 
cur.link(scene_dummy)
scene_dummy.makeParent([orender,ob])

scene_dummy.setEuler((-3.141593/2, 0.0, 0.0))
scene_dummy.SizeX=0.2
scene_dummy.SizeY=0.2
scene_dummy.SizeZ=0.2

Maybe this helps, maybe not ?? the lines don't wrap correctly in the code tags so it mucks up the code a bit