Chromanator Tutorials: Chromanator Misc
Creating the TRON glow
The 1982 movie TRON remains a cult favourite, not least for its highly innovative and groundbreaking visual effects, many of which are still impressive today. As one of the few 80s films to pioneer the use of CG it holds an important place in the history of special effects.
And so here is a tutorial showing how to create the unique ‘TRON glow' effects using Chromanator…
The techniques used in this tutorial will presume that you have filmed footage in the same manner that TRON was filmed. By designing sets and costumes that used only black and white, the effects technicians were able to turn the white markings into the glowing ‘circuitry' as seen in the movie. Thanks to Chromanator you are not restricted to filming in black and white or only using monochrome sets, but you will still need to design high contrast areas to represent the circuitry.
Defining the lines
The guys working on TRON had the unenviable task of having to manually mask every single frame and paint in the glow essentially by hand. With digital compositing this is no longer necessary.
The first thing to do is create a matte for the glow, based on the original clip.
In addition to the clip, we also need a simple green card to place behind the image. This can be created in any image application such as Photoshop. Be sure to make it large enough to fill the frame.
- Place the clip and the green card onto the timeline, with the clip on top.
- Select the clip and switch to the Object View by pressing F2.
In this example, we only want the glow to affect the black lines on the suit, not the black surroundings of the image. So we need to specify the costume's shape:
- A garbage matte can be used to isolate the costume from the background.
- Inverting the garbage matte will ensure that everything except the costume is removed.
This matte also needs to be applied to the green card.
- Save the garbage matte as a preset.
- The preset menu can be displayed by clicking to the right of the ‘Mask Inspector' heading.
- Switch back to the Project View.
- Select the green card and switch to Object View.
- Load the preset.
This will apply the costume shape to the green card as well.
- Now switch back to the main clip's Object View and go to the Key -> Key toolset.
- Select the Luminosity Key then use the tool's pipette to select the black. This will allow the green to show through the dark areas of the costume.
You may find that using the Super Contrast tool in the Key Grade toolset enhances the blacks, enabling a better key.
By applying a Box Blur Alpha of just 1, to smooth the edges of the key, you will find that you already have a primitive TRON glow. However, there isn't much actual glow yet.
We now want to render the clip with the green showing through. This will create a new clip that we can use to create additional glow elements.
Simply set up your in and out points and render the clip, then re-import it.
Place the new glow clip above the others.
- The next step may be easier if you turn off the two lower tracks using the green LEDs to the left of the timeline, so that you are only viewing the glow clip.
Switch to the Object View and select the Colour Difference Key from the Key -> Key toolset.
- Select green from the tool's drop-down menu and key out the green from the costume.
- It may help to increase the green's saturation in the Key Grade section.
- Finally invert the key so that the green is all that remains.
Switch back to the Project View and display the glow clip's properties.
- Change the Composite Mode to ‘Add'.
Return to the Object View and go to the Effects toolset.
- Select the Box Blur RGBA tool and apply a blur of 40.
Go back to the Project View and copy the glow clip, then paste another two copies directly above it.
- In the top glow clip, change the blur to 2.
- In the second glow clip, change the blur to 15.
The combination of the three glow clips at different blur strengths will have created a nice green aura.
You can now turn on the other layers to complete the effect.
- You can alter the colour of the circuitry and even the individual glow elements using the Hue Shift tool in the Grading toolset.
- Lowering the brightness on the main costume clip can make the glow appear brighter.
Through careful use of masking and garbage mattes you can apply different glows to different parts of the image, building it up piece-by-piece to achieve some really beautiful effects:
All images from TRON are property of the Walt Disney Company. See http://www.tron-sector.com/ for a good source of images and TRON-related information.