Hello everyone,
this came up on the arnold mailing list so I thought lets check back on
the nukeside of things.
worldToCamera and worldToNDC to create a fully functional camera ?!?!
I stuffed all I could find in one script, but the focal length seems to
be wrong.
All is coming from Ivan Busquet, Michael Garret and Frank Rueter I
think, or who is doing all the stuff on the python developers guide ?
(deep bow to you)
I am just looking for some input here, nothing production relevant...
shouldnt it be possible to get the window uv translate out of the
worldToNDC matrix too ?
I know this is kind of an old topic and probably everyone has custom
metadata or a custom fileformat to exchange cameras between apps.
But i still like the idea to get the most out of those two matrices..
Cheers
Johannes
## this script was assembled by j.hezer for studiorakete 2012 all input comes from frank rueter, ivan busquet and Michael Garrett
## still wip with worldToNDC and worldToCamera only
import nuke
import os
import math
def getMetadataMatrix(meta_list):
m = nuke.math.Matrix4()
try:
for i in range (0,16) :
m[i] = meta_list[i]
except:
m.makeIdentity()
return m
def ExrToCamera():
try:
selectedNode = nuke.selectedNode()
nodeName = selectedNode.name()
node = nuke.toNode(nodeName)
if nuke.getNodeClassName(node) != 'Read':
nuke.message('Please select a read Node')
print 'Please select a read Node'
return
metaData = node.metadata()
reqFields = ['exr/%s' % i for i in ('worldToCamera', 'worldToNDC')]
if not set( reqFields ).issubset( metaData ):
nuke.message('no basic matrices for camera found')
print 'no basic matrices for camera found'
return
else:
print 'found needed data'
imageWidth = metaData['input/width']
imageHeight = metaData['input/height']
aspectRatio = float(imageWidth)/float(imageHeight)
hAperture = 36.0
vAperture = hAperture/aspectRatio
# get additional stuff
first = node.firstFrame()
last = node.lastFrame()
ret = nuke.getFramesAndViews( 'Create Camera from Metadata', '%s-%s' %( first, last ) )
frameRange = nuke.FrameRange( ret[0] )
camViews = (ret[1])
for act in camViews:
cam = nuke.nodes.Camera (name="Camera %s" % act)
#enable animated parameters
cam['useMatrix'].setValue( True )
cam['haperture'].setValue ( hAperture )
cam['vaperture'].setValue ( vAperture )
for k in ( 'focal', 'matrix', 'win_translate'):
cam[k].setAnimated()
task = nuke.ProgressTask( 'Baking camera from meta data in %s' % node.name() )
for curTask, frame in enumerate( frameRange ):
if task.isCancelled():
break
task.setMessage( 'processing frame %s' % frame )
#get the data out of the exr header
wTC = node.metadata('exr/worldToCamera',frame, act)
wTN = node.metadata('exr/worldToNDC',frame, act)
#set the lenshiift if additional metadata is available or manage to calculate it from the toNDC matrix
#cam['win_translate'].setValue( lensShift, 0 , frame )
# get the focal length out of the worldToNDC Matrix
# thats the wip part any ideas ??
worldNDC = wTN
lx = (-1 - worldNDC[12] - worldNDC[8]) / worldNDC[0]
rx = (1 - worldNDC[12] - worldNDC[8]) / worldNDC[0]
by = (-1 - worldNDC[13] - worldNDC[9]) / worldNDC[5]
ty = (1 - worldNDC[13] - worldNDC[9]) / worldNDC[5]
swW = max( lx , rx ) - min( lx , rx ) # Screen Window Width
swH = max( by , ty ) - min( by , ty ) # Screen Window Height
focal = hAperture / swW
cam['focal'].setValueAt( float( focal ), frame )
# do the matrix math for rotation and translation
matrixList = wTC
camMatrix = getMetadataMatrix(wTC)
flipZ=nuke.math.Matrix4()
flipZ.makeIdentity()
flipZ.scale(1,1,-1)
transposedMatrix = nuke.math.Matrix4(camMatrix)
transposedMatrix.transpose()
transposedMatrix=transposedMatrix*flipZ
invMatrix=transposedMatrix.inverse()
for i in range(0,16):
matrixList[i]=invMatrix[i]
for i, v in enumerate( matrixList ):
cam[ 'matrix' ].setValueAt( v, frame, i)
# UPDATE PROGRESS BAR
task.setProgress( int( float(curTask) / frameRange.frames() *100) )
except:
print 'select at least one read node'_______________________________________________
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