Join Steve Wright for an in-depth discussion in this video Which math operation to use and when, part of VFX Keying: Master Course.
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- [Instructor] When merging keys together,…you have to pay close attention to which…math operation you use.…Some will replace one key with another,…others will add them on top of each other,…while others can build up…alpha channel values greater than one,…which you never want to happen.…So let's push in here…and take a look at this plus operation setup here.…I'm going to connect my viewer here…and open up the sampler node so we can see what's going on.…So here's my setup.…I have these two ramps that go from zero to 1.0.…
Now the sampler node, set right over here,…is simply sampling the entire scan line from left to right…and plotting it up here.…So this is saying on the left edge I've got zero…and on the right edge I've got 1.0…and it's kind of a nice linear ramp.…Here's my channel merge node…where I'm going to plus them together.…And this shuffle just brings them out of the alpha channel…into the RGB so the sampler can see them.…Sampler doesn't do the alpha channel.…So let's hook up this guy here…and you immediately saw the viewer get bright…
Note: This course was created by Steve Wright, author of the seminal book, Digital Compositing for Film and Video. We are proud to host this course in our library.
- Creating an uber key
- Keying green-screen vs. blue-screen footage
- Preprocessing footage
- Building a clean plate
- Making luma keys
- Keying on hue and saturation
- Pasting keys together
- Grain management
- Saving time with garbage mattes
- Using spill suppression
- Improving edges
- Color correcting keys
- Sweetening the comp
- Alternative compositing workflows
- Fixing edge problems
- Using KEYLIGHT, Primatte, Ultimatte, and other tools
Skill Level Intermediate
Photorealistic Lighting with Maya and Nukewith Mark Lefitz2h 24m Intermediate
NUKE Compositing: Sci-Fi Force Fieldwith Steve Wright2h 12m Intermediate
1. Keying Workflows
2. Pre-Processing the Green Screen
3. Other Types of Keys
4. Building the Uber Key
5. Spill Suppression
6. Compositing Techniques
7. Color Correcting
How to match grade two clips4m 15s
8. Workflow Examples
9. Sweetening the Comp
10. Fixing Edge Problems
11. Special Keying Solutions
12. Appendix: Keyer Tutorials
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