VRay EXR to Nuke Camera

[BEIGE]

awesome - thanks, it works now. This is amazing, not having to deal with FBX camera nodes at all. My plates are matched perfectly.

[pechart]

Yes. It's one of the greatest workflow improvements in the last 1 or 2 years for me.

[kagemaru]

Ehi guys, i'm trying to get this working with nuke 7 (outputting from max though), but apparently i can't create anything.
Any help?
Cheers

[tashko.zashev]

Ehi guys, i'm trying to get this working with nuke 7 (outputting from max though), but apparently i can't create anything.
Any help?
Cheers

Did you got it to work? I see few posts earlier that Stephen has managed to get correct result from Max as well.

[kagemaru]

Did you got it to work? I see few posts earlier that Stephen has managed to get correct result from Max as well.

Actually no, i've just tried with latest renders from vray 2.40.04 (last stable build for max) and nukex7.0v5 but it just outputs "no metadata for camera found".
I haven't deeply investigated, but with a ViewMetaData node i can see camera informations are in there, something's wrong with how the script reads the file (at least in my case).

Ps
We use standard cameras, not vray ones.

[EDIT]
I think i managed to catch what was wrong: basically in my files metadata "FocalLenght" is defined as "Fov", changing names worked. There's still something strange about rotations (even pluggin -90 x axis rotation doesn't look right), i'll try to see if i can match an fbx camera i used (which i'm sure is doing things right).
Don't know if this difference has happened on vray or nuke side.

[kagemaru]

Actually no, i've just tried with latest renders from vray 2.40.04 (last stable build for max) and nukex7.0v5 but it just outputs "no metadata for camera found".
I haven't deeply investigated, but with a ViewMetaData node i can see camera informations are in there, something's wrong with how the script reads the file (at least in my case).
...
[CUT]

Ok so i figured out also the rotation stuff, i had to cut out the part of the script where he manipulates the rotation matrix (i have to be honest, i don't know much about them) and since i was on it i already put an axis node connected to the camera that does the Y up switch and also set the vertical aperture that was missing.
In this way my fbx camera and the one extracted from exr match.
This has been tested with nukeX7v0.5 and renders from Max (sorry for the cross post).

import math
import nuke
import nukescripts


def createExrCamVray():
    '''
    Create a camera node based on VRay metadata.
    This works specifically on VRay data coming from maya.
    '''
    
    #Big thanks to Ivan Busquets who helped me put this together!
    #(ok, ok, he really helped me a lot)
    #Also thanks to Nathan Dunsworth for giving me solid ideas and some code to get me started.
    
    ### TODO : add progress bar (even though it's really not needed here) that works
    
    node = nuke.selectedNode()
    mDat = node.metadata()
    
    # reqFields = ['exr/camera%s' % i for i in ('FocalLength', 'Aperture', 'Transform')]
    reqFields = ['exr/camera%s' % i for i in ('Fov', 'Aperture', 'Transform')]
    if not set( reqFields ).issubset( mDat ):
        print 'no metadata for camera found'
        return
        
    first = node.firstFrame()
    last = node.lastFrame()
    ret = nuke.getFramesAndViews( 'Create Camera from Metadata', '%s-%s' %( first, last )  )
    fRange = nuke.FrameRange( ret[0] )
    
    nukescripts.clear_selection_recursive()
    
    myAxis = nuke.createNode('Axis2')
    myAxis['rotate'].setValue(-90,0,0)
    
    cam = nuke.createNode( 'Camera2' )
    cam['useMatrix'].setValue( False )
    
    for k in ( 'focal', 'haperture', 'vaperture', 'translate', 'rotate'):
        cam[k].setAnimated()
    
    #task = nuke.ProgressTask( 'Baking camera from meta data in %s' % node.name() )
    
    for curTask, frame in enumerate( fRange ):
        #if task.isCancelled():
            #nuke.executeInMainThread( nuke.message, args=( "Phew!" ) )
            #break;
        #task.setMessage( 'processing frame %s' % frame )
        
    
        # IB. If you get both focal and aperture as they are in the metadata, there's no guarantee
        # your Nuke camera will have the same FOV as the one that rendered the scene (because the render could have been fit to horizontal, to vertical, etc)
        # Nuke always fits to the horizontal aperture. If you set the horizontal aperture as it is in the metadata,
        # then you should use the FOV in the metadata to figure out the correct focal length for Nuke's camera
        # Or, you could keep the focal as is in the metadata, and change the horizontal_aperture instead.
        # I'll go with the former here. Set the haperture knob as per the metadata, and derive the focal length from the FOV

        val = node.metadata( 'exr/cameraAperture', frame) # get horizontal aperture
        fov = node.metadata( 'exr/cameraFov', frame) # get camera FOV
        imHeight = node.metadata( 'input/height', frame) # get image height
        imWidth = node.metadata( 'input/width', frame) # get image width

    
        focal = val / (2 * math.tan(math.radians(fov)/2.0)) # convert the fov and aperture into focal length
        vAper = val / ( float(imWidth) / float(imHeight) ) # get the camera vertical aperture

        cam['focal'].setValueAt(float(focal),frame)
        cam['haperture'].setValueAt(float(val),frame)
        cam['vaperture'].setValueAt(float(vAper),frame) 

        matrixCamera = node.metadata( 'exr/cameraTransform', frame) # get camera transform data

        #Create a matrix to shove the original data into 
        matrixCreated = nuke.math.Matrix4()
        
        for k,v in enumerate(matrixCamera):
            matrixCreated[k] = v
        
        # matrixCreated.rotateX(math.radians(-90)) # this is needed for VRay.  It's a counter clockwise rotation
        translate = matrixCreated.transform(nuke.math.Vector3(0,0,0))  # Get a vector that represents the camera translation   
        rotate = matrixCreated.rotationsZXY() # give us xyz rotations from cam matrix (must be converted to degrees)

        cam['translate'].setValueAt(float(translate.x),frame,0)
        cam['translate'].setValueAt(float(translate.y),frame,1)
        cam['translate'].setValueAt(float(translate.z),frame,2)
        cam['rotate'].setValueAt(float(math.degrees(rotate[0])),frame,0)
        cam['rotate'].setValueAt(float(math.degrees(rotate[1])),frame,1) 
        cam['rotate'].setValueAt(float(math.degrees(rotate[2])),frame,2)

Thanks for this useful script guys.

[tashko.zashev]

Hi again,

Thanks for the update, good to know that.

[DPS]

Regarding using this in Max (and excuse my lack of understanding of Nuke), I'm getting a message saying:



createExrCamVray() takes exactly 1 argument (0 given)

Traceback (most recent call last):
File "<string>", line 1, in <module>

[ronald_a]

tashko.zashev Is there any chance somebody has this updated to work with nuke 13?

[tashko.zashev]

tashko.zashev Is there any chance somebody has this updated to work with nuke 13?

I don't know If someone has an updated version of the script.