One of the main elements in this film is the magical rainbow lights that pour out of Quinn's wardrobe. on top of this effect, there are many shots and environments that would take a normal renderer weeks to complete. So I have opted to uses Unreal Engine 5. Unreal Engine 5 has a new lighting system called Lumen. Lumen uses surface caches to produce accurate light maps to produce real time, close to perfect realistic lighting. But it has its limitations.
The wardrobe needed to squash and stretch in a really cartoony way to sell it coming alive. to achieve this our rigger used a lattice deformer and we export the animation using an Alembic Cache. Only to later find that Lumen cannot support Alembic Caches due to the animation being baked on to the geometry.
To counter this problem I tested out using an FBX version for when the model is stationary and switching it to the Alembic Cache when it is moving about. This didn't work due to the huge difference in lighting. So I ended up keeping the Alembic Cache throughout the whole sequence. Which strangely works, the lack of realistic lighting
makes the wardrobe stand out from the background, drawing the audiences eye.
The next issue was the lights. As most people know, if you take every colour of the rainbow in light form and shine them all together you get a white light.
I very quickly discovered that the UE5 emission lights, although had their flaws, were still the best way to achieve the rainbow light effect.
Once I was happy with the effect, I produced a test render. The side that I had done all the tests on worked amazingly but the other side of the wardrobe didn't work and I realised it was picking up no light at all. The wardrobe Artist and I soon discovered that the the Normals on the wardrobe had changed direction upon import, and that we needed to tick the "recompute Normals" box when we import Alembic Caches.
After that slight hiccup, I carried on with the renders. An issue I wanted to sort out was the brightness of the light. I wanted it to look like the Ark of the Covenant opening in "Raiders of the Lost Ark" not a door opening with some lights behind it, make it more cinematic. This was achieved by enabling Bloom to the camera. Through adding a slight bloom to the camera, the rainbow light becomes more intense and cinematic and give me exactly what I was trying to get.
This effect took a week to achieve and had around 5gb worth of test renders. This probably couldn't
be done without using Unreal Engine's amazing power.
Final Render with Bloom