How to make a magic witch blast

Behind MR. X’s visual effects for ‘WandaVision’.

befores & afters’ visual effects coverage of WandaVision continues with this insight from MR. X VFX supervisor Ralph Maiers, who oversaw his studio’s work on the magical sequences during the flashback reveal of Agatha’s (Kathryn Hahn) true identity.

Find out how a typical magic blast was made, including the FX sim process, as well as how Agatha managed to take the life force out of her witch coven cousins.

b&a: Tell me about the kind of discussions you had about the magical visual effects surrounding Agatha for the scenes MR. X worked on?

Ralph Maiers: We were assigned the origin story for Agatha Harkness, which is Agnes converting to Agatha the witch. Because it was origin story, we knew we wanted it to be kind of witchy and kind of like Scarlet Witch, which is magic, but something different. So we had a whole design phase that we had to go through. We’d consider, well, what’s different about her magic from Scarlet Witch and what different kinds of elements does the Scarlet Witch hold in her canon that isn’t in the normal witchery world?

© Marvel Studios 2021. All Rights Reserved.

Our concepts initially were very magical—more like magic at the hands and the magic at the object that you’re affecting, but less magic in the middle. We ended up developing into a much more of a beam-y kind of a direct attack tendril-y kind of look. It was a real creative arc, both in color and design.

b&a: In the flashback scene you also see other witches that Agatha drains the life out of – how did you do that?

Ralph Maiers: They start to desiccate and be sucked dry by Agatha’s magic during her origin story. We had to create a bunch of blend shapes and matchmoving objects. I think we had eight different characters that we had to rig and matchmove. And then we even had skin tracking on a lot of those witches, including Agatha for some of the inner glow effects that we were doing.

© Marvel Studios 2021. All Rights Reserved.
© Marvel Studios 2021. All Rights Reserved.

The witches started out with the actual actors and luckily Marvel had scanned them all. Then we recreated the set and recreated the characters so that we had matchmoves for lighting. All that interactive lighting needed to happen. There were four witches that were full matchmoves and ended up being full CG transitions, which were these desiccation kind of blend shaped warps or morphs.

b&a: When blasts of magic come from Agatha and others, how did MR. X handle that work as particle FX?

Ralph Maiers: The beams were created in Houdini utilizing a wide array of particle advection techniques for the different tendril like twisting streams that occur throughout the EP. #109 sequence.

The initial setup was poly line based and advection occurred along the tangent of the poly lines and forces were used to direct the emissions along the associated paths. The origins had emissions that we utilized to establish the conical tear drop shape that showed directed force in the direction of Agatha. At the impacts we created a shunt and kill for any bouncing particles to keep the attack feeling lethal and directed into Agatha.

© Marvel Studios 2021. All Rights Reserved.
© Marvel Studios 2021. All Rights Reserved.

We were careful not to make this too invasive as we were playing to a family friendly viewership. The beams went through many design phases from a more languid colorful ethereal sinusoidal wave to a dark simplified color pallet with a significant directional advection. Impacts on Agatha where also explored, ranging from destructive emulation events to a less intense swirling contact point that we used to portray a penetration without too much direct vivisectional display. MR. X used a tight match moved interactive lighting pass to reveal the under skin and under garment glow of beam penetration.

b&a: What kind of interactive lighting did they have on set for this?

Ralph Maiers: They had a whole color coded system that they had shot on set, but we quickly threw that out. Not that it was a bad thing—we had three different types of beams and three or four different colors that we had established as the base for the witches’ coven. Each one had their own kind of beam style. And each one had their own color and then it all kind of coalesced at Agatha.

© Marvel Studios 2021. All Rights Reserved.
© Marvel Studios 2021. All Rights Reserved.

It was beautiful, but the problem was that it was taking the onus off Agatha and she’s really got to be the star of the show. And I think they were very smart in deciding that they needed to make the coven colors all kind of the same, so that Agatha’s color could easily be defined as the dominant power. So we ended up going through some testing to decide what that color should be and then what her color should be.

b&a: Those particle sims look amazing, and it’s often always a lot more complicated I think than people realize.

Ralph Maiers: Yeah, I mean, just the particles count. When you look at those scenes, it looks pretty simple. Especially when I watched it on TV, it was like, Oh, it’s over already.

The particle counts were up in the range of 120 to 150 million particles. And that was a tonne of management that had to be done. And we had multiple times that we had to do re-times on those large sims. Luckily some of the guys had borrowed an old cache re-scaler.

© Marvel Studios 2021. All Rights Reserved.
© Marvel Studios 2021. All Rights Reserved.

I don’t know if you’d call it an expansion/compression system, but they upgraded it and were able to use it for this. We were able to fairly quickly re-time these effects if editorial threw us one of those, ‘Oh, hey, by the way, we decided we were going to make that 20 frames quicker.’ Instead of having to go all the way back to animation and FX and start over, we could just return those caches, which really helped.

We used it on both the animation and the FX caches, so that after you’re done with your sim, you can actually manipulate them and say, if you need, rather than 50 frames, you need to be 60 frames, then it’ll interpolate those changes and then you can re-run it.

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