ENDA Episode 211 → The time when ENDA fights with a fire sword (Part 3)
Some FX simulations might not come with a usable alpha channel. And even when they do, it often won’t include the correct transparencies. That’s why we need to reconstruct it from the channels we already have.
In a previous episode, we mentioned that the next step was dealing with the alpha channel, or rather, the lack of a proper one.
Some FX simulations might not come with a usable alpha channel. And even when they do, it often won’t include the correct transparencies.
That’s why we need to reconstruct it from the channels we already have.
In the video below, you can see how shuffling the RGB from channels like density or flame can produce surprisingly solid alpha mattes. From there, we can merge them together to build a more complete alpha for the simulation.
Even better, we can tweak each matte individually with Multiply or Gamma nodes, controlling how transparent each part of the effect should be.
Once that’s done, we copy the new alpha into the main pipeline and premultiply it. The edges immediately sit more naturally in the plate, and having a cleaner alpha also makes it far easier to colour-match the FX into the shot.
An important step that would need its own episode.
So, stay tuned!
The journey continues...
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