Showing posts from August, 2012

2D Volumetric rays in nuke

2D Volumetric rays
Here i'm going to explain Creating 2D Volumetric rays in nuke.

As a compositor and 3D artist every one really love Volumetric rays. Creating Volumetric rays in 3D packages such as Maya, 3dMax and any other 3D software’s are quit expensive. Its took long time to render for producing nice Volumetric rays.

Creating 2D Volumetric rays doesn’t look nice like rendered in 3D packages. But we can save some valuable times by create this effect in 2D.

You can create nice Volumetric rays effect like above image in Nuke. I used "Godrays" "Noise" and "roto" nodes to produce above result.

Here we go............

Step-1. Import image into nuke.

Step-2. Draw a roto shape to the light. If you have matte (alpha) will use that
            instead off roto.

Step-3. Add "GodRays" node and connect it to "roto" node. Move the center point
            to the opposite  direction off rays direction. Here i placed the center

chromatic aberration

chromatic aberration Most people doesn’t understand What is "chromatic aberration"and struggle to handle it on post production. Here is simple solution to understand and produce good result in post.
First is first..
What is chromatic aberration?
Chromatic Aberration, also known as “color fringing” or “purple fringing”, is a common optical problem that occurs when a lens is either unable to bring all wavelengths of color to the same focal plane, and/or when wavelengths of color are focused at different positions in the focal plane.
for more info:
Look below image Right side. You can see the red color (fringing) bleeds on the object edges.Its because of chromatic aberration.

 How its happen?
Chromatic aberration is caused by lens dispersion, with different colors of light travelling at different speeds while passing through a lens. As a result, the image can look blurred or noticeable colored edges (red, green, blue, yellow…

Getting roto shapes name

Getting roto shapes script will print all the "Roto" shapes and "Layers" name in all the Roto nodes.  This script goes down 4 child layers deep and get all the shapes and layers. If want to go further you can add some more by editing this code. def gettingRotoNames():
    for rpNode in nuke.allNodes('Roto'):
        cKnob= rpNode['curves']
        root = cKnob.rootLayer
        print '\n' +
        for e in cKnob.rootLayer:   
            print ' - ' +
            if isinstance(e, nuke.rotopaint.Shape):
                for i in cKnob.toElement(
                    print '   - ' +
                    if isinstance(i, nuke.rotopaint.Shape):
                        for o in cKnob.toElement( + '/' +
                            print '     - ' +