Building the Grand Staircase “For Real”

Let’s return to my efforts with the separate model of the grand staircase from the first two films, as described in this post. With mockups and tests out of the way, it’s time for a real attempt at modeling the grand staircase! All of the flights of stairs in that room (other than a few at the bottom) have identical designs and dimensions, so I’ll be able to do a lot of duplication here. We’ll start off simple:

Cool. Next comes the room itself, or at least a very basic start at representing its shape. Starting to duplicate some elements, throwing in some basic lighting and coloration…

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Yeah, this is gonna work. I decided from the get-go that I wanted this side project to be geared toward Blender’s Eevee render engine, rather than the slower but more realistic Cycles engine I normally use. Makes it a lot quicker to churn out renders as I go.

I started messing with the animation early on. This adds a whole different level of complexity to the project, since the motion of the stairs also affects the configurations of the handrails…and typically when one flight moves, another has to move to get out of its way…but the flights can’t all move simultaneously without colliding into each other…yeah, it’s tricky. Still, I was able to get the first few flights working with fairly minimal “cheating” – here are two views with all the swiveling stairs (so far) in their two main positions.

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To help you get oriented, the long landing at the bottom right (with the baluster shadows on it) is where Harry and friends first emerge into this room. I just haven’t built the archway through which they enter, or the rest of the set beyond. The first render reflects the way the model was built; the second reflects the alternate positions after the stairs have rotated.

One thing that helps with this is that I’ve activated backface culling for the room itself. In computer graphics, each surface “faces” a particular direction; we call this the normal. Ordinarily you can see the surface from either side, but with backface culling, you can only see it from its “front” side. I built the room so its normals all point inward, which means you can always see into the room, no matter what angle you’re at.

I paused work on the staircase to switch back to some of the other stuff I’ve more recently posted about, and that’s when I hit a snag…another fan turned me on to some old issues of Cinefex magazine that describe “an eighth-scale, forty-foot miniature, laid on its side to aid construction and photography” (#88, regarding the first film) and “a 40-foot-long staircase miniature built previously” and reassembled as it was before (#93, regarding the second film).

This stumped me. Hard. The model was indeed laid on its side, but at 1:8 scale, the various real-world items strewn about in construction photos would look much, much larger than they do. And if the miniature still measured 40 feet along its longest side at 1:8 scale, that would make the “real thing” 320 feet tall…and by my calculations, it should only be in the low 200s.

Ultimately, I’ve decided to press forward with my original dimensions, essentially disregarding the Cinefex figures. My best hypothesis is that the reference to 1:8 scale is incorrect – probably a misreading or misremembering of 1:3 scale – and the 40-foot figure isn’t the distance from the room’s bottom to top, but from the open wall nearest the Great Hall to the opposite wall with the large window. That math actually works perfectly if the scale was indeed 1:3.

So I continued building the rest of the flights of stairs. It turns out a little more “cheating” is necessary than I originally hoped…some of the balustrades are going to have to magically pop out of nowhere. But then again, the castle is magical. And the only alternatives are to leave unprotected ledges 200 feet up (yikes) or to have some of the balustrades sweep right through the landings, knocking off any students in their way (yikes again).

In any case, I’m mainly focused on the configuration in which the model was built; all the stair movement was digital (other than the one full-sized flight on the set that actually moved). The movement is just a bonus. With all the flights in place, it looks something like this:

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The walls, floor, and ceiling are still just placeholders, really, and I haven’t added the lamps below the landings yet. But the stairs themselves are all accurate! Notice how they form two unconnected spirals that switch sides at the top and bottom. In a future post, we’ll add more detail to the rest of the room, and maybe some less generic materials. Then come animations and flythrough/around videos!