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…

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.

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:

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!

My Hogwarts Model Featured in “Les Fondateurs 2” Teaser!

The teaser trailer for Les Fondateurs: La Quête de Gryffondor is out! Spoiler alert: there’s a brief shot of Hogwarts at the end, courtesy of yours truly. I’m really looking forward to producing more shots of the castle for this fan film!

Fun facts about the animation, which was created specifically for the teaser:

This was created using a copy of the main model. I removed everything that wouldn’t be visible, since I wasn’t using a render farm and I wanted to keep the render times decently fast. (We intend to use a render farm for the film itself, and I also plan to bake a lot of the procedural textures to images, which should speed things up. By then Blender will have adaptive sampling as well.)
This shot includes some parts of the castle that weren’t/aren’t complete in the main model – I built some geometry that would work for this brief shot, but there are some inaccuracies. Fortunately, the castle does change over time! In any case, the model used for the film itself will be more detailed and accurate.
There are no volumetrics in this shot – all the fog was a composited mist pass, plus an overcast HDRI for the sky and lighting. (Thanks, HDRIHaven!)
I removed the pipe that sticks out of Gryffindor Tower…it looked funky from this angle and distance.

I’m looking forward to seeing this project come together!

The POA Clock Tower Approaches Completion

More staircase stuff to come, but for now, back to the main project! With my clock tower photogrammetry in place, I was able to finish up the clock tower’s entryway, again relying more on shots of the set than shots of the miniature, since that area is really only visible from above or from within the courtyard. Fortunately, the sets seem to match the miniature pretty well here. Even though the miniature as currently installed at Leavesden has the doors closed and portcullis down, I decided to keep mine nice and open. My Hogwarts is a welcoming, friendly place. Just look at all the people.

Awkward. Well, anyway, the details look cool, but it’s hard to see beyond the archway; it gets darker in the shadows. Let’s crank up the exposure a little and move beneath the arch to take in all this stuff that we’ll rarely see otherwise!

The actual interior is still dark and boring, but there’ll soon be big windows on the other side of the room.

Let’s talk about those doors, by the way. John Williams wrote a cue for the scene in which they’re locked to secure the school, and he called it “The Big Doors”. He wasn’t kidding. They’re HUGE – around 67 or 68 feet tall, by my estimation. I’m sure they only built the bottom portion for the set, but in the miniature, they just go up and up and up. Imagine the weight…imagine trying to open or close them by hand…

Anyway, the next step was to add windows on the other faces of the clock tower, as well as the details on the dormers along the roof. (Fortunately, these seem to be very similar or identical to the ones on the roof of the Defense Against the Dark Arts building, which I’ve already created, so this didn’t take long.)

With those finished, there are precisely three details left to add to the clock tower: the big window in the back, a small arch at one of the corners, and another door at another corner. Oh, and probably the clock pendulum, too. So four. But I can’t find good reference for the big window, and there’s no point in putting in the pendulum till I have the big window to silhouette it against…and the placement of the arch and door will depend on the placement of the courtyard, and I’m not going to build the courtyard till I’ve built the ruined fountain in the middle. (No sense in enclosing the courtyard and then having to constantly hide pieces to build the stuff inside.) So the fountain is up next!

A Detour on the Grand Staircase

All right…the main model is still going strong, but I’ve found myself intrigued by a side project: the grand staircase, AKA marble staircase. Much like a parking garage, its interwoven spiraling structures are hard for my brain to visualize, which makes them fascinating to reconstruct.

I’ve specifically focused on the version seen in the first two films…after that, it went through some changes, though those changes remained subtle until Deathly Hallows. But in the first two films, it seems to have been brought to life with the same miniature and full-sized partial set – with digital augmentation. (Incidentally, based off of the few images of the miniature I’ve found, I’m pretty sure it was built on its side at somewhere around 1:3 scale…but don’t quote me on that. If I’m right, that would make the miniature over 50 feet long.) [EDIT: I’ve now found a source that claims it was a 40-foot miniature built at 1:8 scale, which doesn’t seem to work mathematically. I’m not sure what to make of this.]

Initially, my primary goal was to replicate the set. I figured the miniature was kind of its own thing, and I got to work aligning technical drawings and photogrammetry and so forth just for the set. (Each of those small orange shapes is where the camera was for a specific frame from the film…pretty cool to see how the camera moved through the space!)

After more closely studying both films, I came to realize that the available reference material does consistently and explicitly establish the spatial relationships between the set and the miniature. (Thank goodness the different paintings and frames provide excellent reference points!) So I changed tack: the new goal was to create a single model that brought the set, the miniature, and the digital elements together. This was aided by a bit of photogrammetry from Chamber of Secrets that worked WAY better than I thought it would:

So the good news is that I had a lot of information to work with. The bad news is…it was a lot of information! This room is enormous and very repetitive, so it’s easy to get lost in the reference images and forget which staircase is which. I tried to just jump right in with the modeling, but confusion set in pretty fast, so I decided this would just be an exploratory first pass. I kept this mockup simple and not super precise. Still, I kept getting lost, so I spent a long while color coding flights of stairs in both the model and in my reference images. Here’s a glimpse of just part of that process:

It looks like a gaudy mess, but for the first time in my life, I understood the complex geometry of the grand staircase! Things I learned:

In plan view, the stairs form three adjacent squares. The flights that actually move are all part of the middle square.
There were definitely at least 36 flights in the miniature – more likely 38, but I can’t find a clear angle confirming the last 2. Regardless, these cover 19 different levels, each 10 feet high. Almost every levels has 2 landings on opposite walls of the room. (I’m hesitant to call these floors, since Hogwarts isn’t really supposed to have 19 of those…but each landing does have a door…)
In the miniature’s “default configuration”, so to speak, the flights are organized into two separate helical pathways. In the middle floors, these each spiral in a clockwise direction as they ascend on opposite sides of the room. Toward the top and bottom, the two pathways intertwine so they can switch sides. Through most of the model, the two paths are identical; they’re just rotated 180 degrees relative to each other.
The bottom-most level is a bit irregular and doesn’t follow rule #3.
If all the flights that form part of the middle square rotate 90 degrees from their bases, you end up with more of a DNA-like double helix, as opposed to two side-by-side helices.
In the first film, we look all the way up and the stairs seem to continue into infinity. The most distant stairs were added digitally to obscure the top of the miniature. These aren’t part of my model.
In the second film, the camera moves swiftly downward through the miniature; the set is composited in toward the bottom. Below the set are still more stairs; these were created by shooting the miniature again from a different angle and compositing it in as the bottom.

Clear as mud, right? Yeah, it’s hard to visualize. But the rough mockup was a success in that it gave me a clear roadmap for making a serious attempt at modeling the grand staircase. I’ve already begun, and I’m looking forward to sharing the details in a future post! In the meantime, here’s an orthogonal elevation-style view of the mockup, just for fun.

Special Announcement

Something a little different today: I’m thrilled to share that I’m going to be providing Hogwarts visual effects for an upcoming French fan film entitled Les Fondateurs: La Quête de Gryffondor. This is the second film in a series about the founders of Hogwarts and a few shots are going to feature the castle…my castle! It’s still early on, but I’m excited to see this project come together. Here’s the very first promotional image of Hogwarts!

You can learn more about the project (and even help financially) here.

More updates on the main Hogwarts 4D project to come!

The Boathouse Steps Aren’t THAT Stupid

Okay, after some massaging, I’ve gotten the photogrammetry meshes to line up a little better. This is always tricky because:

The photogrammetry isn’t precise down to the millimeter – depending on the source images, the model can end up a little skewed.
The technical drawings aren’t super precise either – for most areas, I don’t have detail drawings, only the overall floor plan.
When lining up one photogrammetry mesh with another, you might need to adjust any or all of the following:
- overall scale
- x translation
- y translation
- z translation
- x rotation
- y rotation
- z rotation

So, bottom line…these things aren’t as precise as one could wish, and you have to decide which which sources to trust, and that can vary from area to area.

Anyway, the adjusted photogrammetry confirms that different flights of the Half-Blood Prince boathouse steps (which are the same as in the previous two films) do indeed have different slopes, which is why my vertical dimensions weren’t working very well. In fact, to get everything to fit, I had to give almost every flight a slightly different slope. This seems awfully messy, but it also provides the best fit to the actual miniature.

That’s all being put on hold for now, though – I just discovered more reference photos that are helping me fill in areas that were otherwise difficult to reconstruct. In particular, I finally know what the original “link building” looks like! (That’s the small connection between the Great Hall/Chamber of Reception structure and the marble staircase tower; it changed to a different design after Azkaban.) So while I don’t have any renders to share for this post, I think the next one will cover the link building and the front of the quad building!

P.S. For the record, the boathouse steps themselves are actually a great design, beautifully executed in all three incarnations. I just get frustrated when I can’t get my sources of info to agree with each other, haha.

Great Hall Balconies, Pepperpot, & Pre-DH Boathouse

Work continues on the Prisoner of Azkaban iteration of Hogwarts! I guess my return to the project might have legs.

(Forgive the exposed interior glow panels on the right again.)

With the Chamber of Reception complete, I moved on to the terraces or balconies surrounding the Great Hall, plus the foundations below. Good lord, the geometry of these corbels gave me a headache as I tried to reconcile a variety of imprecise measurements and calculations. I’m pretty happy with how they turned out, though. And I sure was thrilled when the spacings of the corbels and the torches lined up! I added the finishing touches to the pepperpot as well.

This also afforded the opportunity to check out some angles not seen in the films, such as this nighttime view looking toward the head of the Great Hall from the balcony outside:

Soon I was faced once again with that perennial question: what next? At first I considered doing the crenelations outside the Chamber of Reception and the steps down to the boathouse, but as I assembled reference images, I found myself drawn to the boathouse itself.

It’s a simple structure with a lot of good reference out there, since it never changed till the digital rebuild of the castle for Deathly Hallows (when it was completely redesigned), and visitors to the Warner Bros. Studio Tour can get quite close to that part of the model. As a result, it came together pretty quickly. Here it is in complete form:

I really like that last one. I wanted the boathouse to “pop” in front of the similarly-colored castle behind it, so I went with a shallow depth of field and ended up with this render that kinda looks like a miniature itself. You can even see the witch-and-black-cat weather vane at the top. And, as I mentioned last time, I finally got a decent stone floor texture going, though I’ll probably still tweak that some more.

Next up…the boathouse steps, I suppose? Speaking of which, it just occurred to me that the first-years have to climb the height of a 14-story building to get from the boathouse to the Great Hall for their Sorting. Between that and the nerves, it’s amazing they all manage to stay on their feet.