Sorcerer’s Stone Corrections & More Astronomy Tower

Sorry for the delay in this post. Loooooots of stuff going on in my personal life – some of it really good, some of it not so much.

I was slowly working on the Astronomy tower in the midst of all that when this spectacular YouTube video dropped on the official Wizarding World channel. The never-before-seen photos of the original castle inspired me to revisit some areas, the first of which I documented in this video of my own:

I’ll warn you that it’s a slow video, but I got requests for some modeling without the usual time lapse speedup, so…there ya go. Here’s the unadulterated render from the end of the video.

I’ve got more fixes to make based on the new photos, but I’ll save those for a later post and round this one out with a bit of Astronomy tower progress.

There’s a lot of detail in the main turret where several important Half-Blood Prince scenes take place. Here’s an interesting “deconstructed” view as I start to build the area that also existed as a full-scale set. This is the lower level where Harry hides during the climactic confrontation, but without anything added above it yet:

Funnily enough, this is closer to how the book version of the tower would look, in that it’s got a flat top and crenellated ramparts.

One challenge is that the dimensions of the full-scale set don’t quite match the dimensions of the miniature, at least according to the available blueprints. I’m aiming for something of a happy medium – the goal is for it to look the way it does in the film, if a little less detailed.

Here the arches are starting to take shape. These were a little tricky because of the way they curve:

Continued progress on this tower will also have to wait till a future post, but in the meantime I thought I’d at least share something.

Quad Interior Fixes & Starting “Half-Blood Prince”

Short post for today!

I’ve made no secret of the fact that I’m not sure about some of the details inside the quad. It’s hard to find good reference. One particularly mysterious spot has been the wall that cuts the southeast corner at a 45° angle in this old render:

But then I found this video from Plowman Craven, a company that worked on some of the films. About halfway through, there are partial CG models of the OOTP castle. The last few frames of one of the shots give a low-res view of part of that wall. It’s not much, but along with the other glimpses we have, a better sense of what that wall looks like is starting to emerge.

First of all, I’m taking this as confirmation that the big window to the marble staircase was really there – and slightly higher than where I had it. There’s also a horizontal ledge just above it, and the top of the wall descends toward the right. This actually shows up vaguely in a few other images, now that I look again. It even looks like there might be multiple levels to the flat triangular roof area.

Anyway, I still don’t have anywhere near as close a look as I’d like, but here’s my revised attempt at recreating that wall as it might have appeared in the first three films.

In GOF through HBP, it would have looked similar; the floor was just moved up and the cloister removed.

Speaking of HBP…let’s start that version of the castle! There were numerous changes in this film, but by the far the most prominent one in the final cut of the film is the new astronomy tower. Here I’m prepping the surrounding areas:

The Durham section’s central tower (toward the right) has been shortened by 24 feet so that there are only 3 rows of small windows in the middle section rather than 5. I’d imagine this was for the sake of balancing the silhouette with the new astro tower.

But that tower is going to be a project unto itself, so I think I’ll save that for the next post!

The…Gulp…Original Quad

The quad is tough.

There’s just no getting around it. Also known as the paved courtyard or Gloucester courtyard, this squarish space is nestled within one of the castle’s main buildings, between the marble staircase tower and Gryffindor Tower. It survived through all the films, but not without significant changes.

The later iterations are simpler and better documented. They even provide some valuable clues about the earlier designs. But there are outstanding questions about those earlier designs, for which reference is very scarce.

Based on the overhead shot from Chamber of Secrets, the original quad was ringed by cloisters and sat deeper within the building. One interesting result is that the big arch near the grand staircase tower couldn’t have led into the quad as it did in later versions. Best guess based on the available information is that this path ended some sort of balustrade, allowing students to look down into the quad, some 60 feet below.

You can get some sense of it as I start to rough out the geometry inside the original quad. Notice how high up that arch is, relative to the floor:

It’s a little easier to see if we take a look at the front of the castle (and get the viaduct out of the way):

See that shaded wall below the archway? Yeah…the quad floor is all the way down at the bottom of that wall. Crazy low, right? That depth is taken from photogrammetry of the COS overhead shot, by the way. It almost perfectly matches the elevation of the terrace in the back of the building.

Anyway, the regular spacing of the Gloucester Cathedral-inspired windows within the quad forced me to adjust the roofs a bit. The results should be more accurate now than they were before. Here’s an untextured work-in-progress view as I attempted to work out all the spacings and block in the cloisters below:

The balustrade in the foreground is conjectural. The closest thing I have to evidence of its existence is an aerial illustration of the castle by Michael Bramman for The Sunday Times Magazine. It was done before production on the second film, based on a mixture of blueprints, production stills, limited access to the miniature itself, and “a cardboard model which had enough of the of the basic elements to give [him] an idea of the school in its entirety” (source). This is how he painted the archway:

Certainly some sort of lip there – either a balustrade or a parapet. Impossible to tell. For my model, I’m using the design of the other balustrade nearby, between the Great Hall and the marble staircase tower.

Here’s a fully rendered view, similar to the untextured one above, but with some progress on the windows. These happen to correspond to the corridor to the Fat Lady’s portrait in the first film:

I’ve actually already recreated this window design, way back in 2019, at the base of the quad’s south exterior facade:

But back then, I was working with a lot less reference material, so the results were less accurate. Here’s a somewhat comparable angle with those lower windows redone:

Granted, the differences aren’t that noticeable from this distance. But I still feel better, haha!

The details are easier to make out in this render of the similar windows (and others) inside the quad. Fun fact: this is what you’d see if your face was pressed up against the big window by the moving staircases. Maybe at some point I’ll go back into my model of that space and replace the more generic scenic backdrop outside the window with a more “correct” view like this:

Speaking of that window…I have no direct evidence that it was ever included in the exterior model, but I’m strongly inclined to believe it was/is there. I decided to simply import that window from my grand staircase interior model and adapt it for exterior viewing. I kept the imagined real-world scale from the interior model and based the placement of the window on the GoF-era Noble Collection sculpture of Hogwarts:

As a reminder, here’s what it looks like from the inside:

Of course, please don’t take any the exterior details here as gospel. I’m doing my best to reach reasonable conclusions, but when it comes to the quad, I can’t be anywhere near as sure as I am in a lot of other parts of the model.

Next up will be the actual floor of the quad, the fountain, and the cloisters. I’ll save that for the next post. In the meantime, I’ll leave you with a screenshot of something else I’ve been starting to work on. When this whole project is finally finished, I want to provide multiple modalities for you to explore the castle’s shifting architecture. One of those will be a gallery of renders with buttons that will change between different versions of the castle.

The basic functionality is starting to come together, using some test renders of the incomplete models. It’s been a while since I’ve done any HTML/CSS/JavaScript coding, so it’s fun dipping my toes back into that pool while Blender is rendering.

Side Project Complete: SS/COS Grand Staircase

Haha! It’s finished – the version of the grand staircase from the first two Potter films! Join me for a complete video tour!

To get us to this state of completion, I had to add the remaining doorways on the landings:

Then came the big window at the back. Much of the molding is taken directly from that Oxford design I created in the last post. The scene beyond the window is a bit of a cheat…I just did a nighttime render of part of the main castle model, blurred it, and dropped it in like a scenic backdrop in a real set or miniature. It’s not perfect but it gets the job done.

With these elements in place, the only thing remaining was the paintings…but I decided they’d be too much work, I’m omitting them, at least for the time being. They don’t have anything to do with my main purpose (understanding the geometry of the stairs) or my secondary purpose (examining the scale of the space).

Speaking of which, here’s the long-awaited scale comparison between the castle exterior and the grand staircase interior!

They kinda almost fit together at the intended in-universe scale! Of course, if you include all the digital extensions at the top or the extra miniature passes used to extend the bottom, that all goes out the (beautifully mullioned) window. But I think that’s kinda okay.

This concludes my work on this side project…it’s been a fun one! Now back to the main castle model.

SS/COS Moving Stairs, Continued

Let’s take a detour back to the moving staircases of Hogwarts! Thus far, as seen in this post, the environment has been very generic – just a tall rectangular space of the correct dimensions. Let’s fix that.

The biggest problem – we’re talking physically biggest – is that there’s supposed to be an extra chamber in the bottom section where the big window goes. Even if I’m not going to add the window yet, I can at least add that chamber:

Notice also the addition of a blue screen floor. This sits at the floor level of the actual set and also corresponds roughly to its footprint. Below that, I’ve lowered the main floor to reflect the slightly greater depth of the miniature. This is important because I won’t have room for the whole window if I leave the floor at set level. (The window only existed in the miniature, as far as I’m aware – though that changed in the redesigned Prisoner of Azkaban set.)

Next step is to hide the blue screen floor and add the lamps that help light the space:

(None of this is intended to look as realistic as the main castle model…the materials are very basic and these are just quick renders with Blender’s Eevee engine, which specializes in speed at the cost of physical accuracy.)

With lamps in place, let’s start adding the passageway that leads to this room from the Great Hall/Chamber of Reception area. (This was not part of the miniature as far as I’m aware, but it most definitely was part of the set.) This area is interesting because the production design draws very heavily on the real world – specifically, the steps at Christ Church Cathedral at Oxford, where the Chamber of Reception interior scenes were shot. You can see this most clearly with the large stone arches, which were built to match the ones at Christ Church, tying the sets and location shoots together into one shared imaginary space. The doors to the Great Hall set use the same arch design as well…a fact I’m grateful for, since the Warner Bros. Studio Tour was kind enough to post detailed drawings of those doors. You can see the same design on the castle exterior model as well, though I haven’t built those parts yet.

As always, things start with a confusing mess of intersecting curves that gradually coalesce into something more recognizable:

One of these arches is used as the entryway to the main room with the moving stairs:

Nice to be able to duplicate the design as needed:

Those rather ghostly outlines are caused by the same “backface culling” feature that allows us to see into the rooms from outside.

With more walls, details, and openings coming together, this area is starting to look quite a bit like the set…

…minus all the paintings, of course. As I see it, I have three basic options with those. In order of increasing difficulty:

  1. Pull a Filch and omit them entirely.
  2. Scatter the walls with a variety of paintings that look right overall.
  3. Try to match the paintings seen in the films, frame by frame, painting by painting (and fill in the gaps with option 2).

I’m currently sticking with option 1, but who knows?

In any case, there’s still more work to be done here. I need to add the rest of those smaller arched openings throughout the room, and I need to add the large, ornate window on the opposite side. Look for those in a future post! I also still hope to do some videos and scale comparisons and whatnot once this side project is complete. I might need to invest in a new GPU before then, since my current equipment is crashing if I try to render any more lamps with Eevee…

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!

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:

  1. In plan view, the stairs form three adjacent squares. The flights that actually move are all part of the middle square.
  2. 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…)
  3. 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.
  4. The bottom-most level is a bit irregular and doesn’t follow rule #3.
  5. 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.
  6. 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.
  7. 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.

Marble Staircase Tower, AKA Dumbledore’s Tower, AKA Turris Magnus

All right…as promised, it’s time for one of Hogwarts’ most recognizable exterior design features to go from simple block-in to fully detailed model. I’m talking, of course, about the marble staircase tower, also referred to as the turris magnus (on the Marauder’s Map) or Dumbledore’s tower. You can go all the way back to Stuart Craig’s original concept sketch for the Hogwarts exterior, and this tower is already there. It’s the biggest tower, the one on the left. A few of the details are slightly different than the final design, but it’s pretty close:

This thing is massive. To give you a sense of scale, in the real-world environment envisioned by the design team, the top is over 600 feet above lake level. The main body of the tower is 92 feet wide. The spire alone is over 200 feet tall, with somewhere around 50 feet of that being the enormous copper finial at the top. For my fellow Disneyland fans…the entire freakin’ Matterhorn would fit inside the spire. Near the top, that smaller triple turret on the left is Dumbledore’s office; the castle’s moving staircases sit below, inside the cylindrical body of the tower. Mr. Craig has readily acknowledged in interviews that there are design choices here that simply couldn’t be built in real life. Fortunately, magic covers many architectural sins, and personally, I think the films are all the better for it. The turris magnus is featured prominently in the very first shots of Hogwarts and it’s part of what made such an impression on me in the early 2000s.

The first detail I wanted to capture was the dormers sitting along the sides of the spire. This is where the ridiculous, over-the-top dragon chase in Goblet of Fire really came in handy, because Harry and the Hungarian Horntail end up on these rooftops, providing closeup miniature shots and even closer shots of a partial set for Daniel Radcliffe to interact with. I decided to incorporate all these details into the dormers, even though the main 1:24 scale miniature probably wasn’t quite this detailed. (The closeup shots were accomplished with other bespoke miniatures on larger scales.)

Let’s also pull back for a wider shot, including some detail work on the finial and the beginnings of work on Dumbledore’s office:

(By the way, sorry for that other spire near the bottom middle, the one that has the copper patina discoloration near the top but no finial. Keeps showing up in renders. Eventually I’ll add the finial, I promise!)

Next came the stepped corbelling at the base of the turrets of Dumbledore’s office, and their own much smaller spires began to take shape as well. This was all slightly complicated by the fact that what few technical drawings I could find were not quite accurate, but I think I got pretty close in the end.

Here’s where I ran into a conundrum, though. As I mentioned, the closeup shots in GOF were accomplished with larger miniatures built just for those shots. As I looked more closely, I realized that the design of these turrets is a little different in these miniatures than in the main miniature – mainly in the design and placement of the windows. I couldn’t decide at first whether to go with the more detailed alternate design seen in GOF (and the theme park versions) or just go off of the main 1:24 model. The former was tempting at first, since the changes were clearly done to help the exterior match the interior sets designed for Chamber of Secrets. Speaking of which, as massive as this whole tower is, Dumbledore’s office is actually still smaller than the actual set. I thought that was pretty interesting. Below is a very simplified version of the interior set (in white) next to the exterior, using the real-world scale of the set and the intended imaginary scale of the exterior. (The vertical protrusions on the right are where the windows are; they didn’t build the sets with full-thickness walls, so they look like they’re sticking out.)

Anyway, the main model’s design won out in the end, and you can see the corresponding simple window designs have been added here. I’m technically still working on the POA version, and the redesigned exterior wasn’t created till GOF; when I get to GOF, I’m sure I’ll build the redesigned version too.

That makes the spire more or less complete, although I may go back in and add in details like roof flashing where Dumbledore’s turrets meet the main spire. For now, I moved on to the main body of the tower, adding corbels and windows:

From there, it was just a matter of building the larger windows that cover the rest of the tower below! In studying my 16,000-pixel-tall collage of reference images for this tower, I noticed that the spire has actually been mounted on the tower at a variety of angles over time, and there were again some discrepancies between the actual model and the technical drawings. This made it harder to figure out the radial spacing of the windows, but in the end, I did some measurements on my old photogrammetry of the castle and settled on there being 18 windows on each floor. Hopefully that’s correct, haha. In any case, here’s the complete tower!

As I continue around this corner of the castle, we’ll next be proceeding to the only other feature that’s as visually important as the marble staircase tower: the Great Hall!