“Forbidden Journey” Dungeon Interior Layout

My arms have still been giving me intermittent RSI problems. But even when I can’t work on the project, that doesn’t mean my computer can’t! I’ve always wanted to figure out the layout of the indoor queue for Harry Potter and the Forbidden Journey at Universal Studios Hollywood, and without floor plans, photogrammetry is the best method I have for measuring it out. So I set up some Meshroom projects, prepared frames from some YouTube videos, and let ’em run while I rested my arms.

All I’ve got so far are the dungeons, on the ground floor. Functionally, these are just a way to get people from the entrance in the front of the building to the greenhouses in the back. In terms of story, these give the rider a chance to see the Mirror of Erised, the statue from the third-floor corridor in the first film, the entrance to Potions, the entrance to the kitchens, and so forth.

Kinda hard to understand what you’re looking at. Maybe a plan view with a faint aerial photo beneath it will help?

Funnily enough, the entrance to the kitchens does seem to be beneath the Great Hall, just as it is in the books.

Anyway, for good measure, here’s a quick flyaround animation:

Of course, this is missing the lockers and the retail space and the ride exit and any number of behind-the-scenes areas that I assume fill out the rest of the ground floor. Maybe someday.

Eventually I’ll do the main part of the indoor queue on the upper levels. Then the hope is to actually build a proper model of the exterior, and probably as much of the interior as I can as well. But since I’m busy with other parts of the H4D project right now, I thought I’d at least share a glimpse of what I’ve got so far.


Cool Link: 3D Winchester Mystery House Tour

Unrelated to Hogwarts, but I thought it might appeal to a few readers – the Winchester Mystery House has made available a 3D-model-meets-Google-Street-View tour of its interior!

If you’re not familiar with this spot, it’s a bizarre mansion in San Jose, California. It came together over decades of unplanned construction under the direction of its owner, Sarah Winchester. Some people take the haunted house angle; personally, I have no belief in the supernatural, but I’m fascinated with the gargantuan house’s architecture – stairs to nowhere, windows from one room into another, doors that open to steep exterior dropoffs, etc.

I always wanted to see the layout of the whole house, but it was built with no master plan and I’d never found any attempts at creating one ex post facto. Now that’s all changed – Matterport 3D Tours spent a weekend capturing the house so that it can be explored digitally in the age of COVID-19. That also means you can get a sense of the floor plan, and although I’m annoyed that the orthographic floor plan view has been disabled, it’s still a dream come true.

Anyway, I’ve already found it to be well worth the $8.99 it costs and I’m looking forward to continuing to explore. If you’re interested as well, check it out at https://winchestermysteryhouse.com/immersive-360-walkthrough/.

Insert legal disclaimer about me not being affiliated with Winchester Investments LLC here, blah blah blah. I’m not getting a cut of their sales – I just think it’s cool as f$%#!

Anyway, more 3D Hogwarts stuff to come!

The Long Gallery & Starting the Bell Towers

Work on my 3D model of the Prisoner of Azkaban castle continues! The area that corresponds to Durham Cathedral’s north transept is now complete:

I shifted my way attention to the adjacent walls that correspond to the cathedral’s nave and north aisle, otherwise known at Hogwarts as the Long Gallery. I was surprised to notice that the windows and buttresses are not evenly spaced. In fact, the upper windows don’t even align with the lower windows. I fought this briefly, thinking I must be mistaken, but nope, I’m pretty positive none of this stuff lines up in the miniature – and not in ways that match the imperfections of Durham!

I wanted to match the miniature as closely as I could, so I started by adding placeholders for the bell towers at the other end of the Long Gallery to help me lock in my spacing:

The stand-ins are shorter than the talent, and their faces are kinda blank, but hey, what are you gonna do.

At this point I discovered that my entire Long Gallery area was about a foot too far east, so I took a few minutes to shift it over and swivel the viaduct accordingly (a whopping 0.25°). A foot’s not a lot – at 1:24 scale, that comes out to half an inch in the miniature – but it helps to line things up as closely as I can.

With that done, I blocked in the walls and roofs of the long gallery:

Then came the details, with all their subtly variable spacing. Here’s an orthographic view from the side – a perspective-less elevation view, in other words. All the misalignment is totally intentional, and it should be pretty accurate (although I made further tweaks after this render).

Of course, it’ll look better once the far side is enclosed as well; I’m not working on that courtyard side yet.

In the meantime, my next task was to create the 15-foot-wide octagonal tower on the roof of the Long Gallery. This was added in Chamber of Secrets; my guess is that it was a purely aesthetic decision, perhaps motivated by the fact that the establishing shot of the greenhouses shows that area more clearly than we had seen in the first film.

Pretty quick add, and it never changed in any of the later films. Just gotta make sure I exclude it from the eventual Sorcerer’s Stone version of the model!

Next up? The bell towers! While the central tower isn’t very similar to the one at Durham Cathedral, the bell towers have a lot more in common with their Durham counterparts, the North and South Galilee Towers. In fact, the basic impression of the original design in the first two films is that they’ve simply knocked a few of the pinnacles off and added a conical roof to each tower. (Closer inspection does reveal some subtle differences in the details, as with all the Durham areas.) In Prisoner of Azkaban, the conical roofs were replaced with taller belfries and octagonal spires that echo the redesigned central tower, but the lower sections still bear a striking resemblance to Durham Cathedral. They also get a lot more intricate than the central tower, which makes them a little intimidating. I decided to start with the bottom portion, which is all based off stuff I’ve already made:

Now for the hard stuff! Okay, it’s not exactly hard…it’s just…a lot.

Halfway there:

The openings are tricky. In some shots in the early films, you can very unambiguously see straight through from one side to another, but in some photos of the miniature from the Warner Bros. Studio Tour, it looks like there are interior walls. After finding other photos that seem to show straight through in the Studio Tour as well, I decided to keep mine hollow, as you see above. Hopefully that’s still accurate to the later films.

Next time we’ll finish the bell towers, add the wall between them, and continue around this northern part of the castle!

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.

Clock Tower Progress & Courtyard Photogrammetry

Let’s continue with the Prisoner of Azkaban clock tower! I created the columns and elaborate moulding below the clock. As you can see in this “work in progress” render, everything was still separate from the building at this point:

But as these areas became more complete, I began placing them correctly along the building. I also discovered some issues with how I’d built the facade last year, so I decided to simply redo some of it altogether. Below, you can see some of the old walls removed for replacement as I maneuvered the new elements into position:

I resisted the urge to simplify some of these details, and I’m glad I did. The results were worth it the effort! This has become one of the most detailed areas of the model so far, mostly because the original design has a lot of details, but also because the available reference material is so good. Maybe it’s a good thing I don’t have detail drawings for most of the castle…everything would take so much longer if I could get this precise with everything:

Fun fact, by the way: see that arch at the bottom of the last render? In the miniature, it’s just got open air behind it, but they created a full-sized set for a shot in Order of the Phoenix, and in that version, it’s actually a balcony. (Umbridge and Filch are standing up there.) They don’t appear to have changed the miniature; I’m going to leave the balcony out.

Moving downward, we arrive at this lovely Gothic pediment that frames the entryway. No technical drawings for this one, so I had to just rely on as many reference images as I could find. Shots of this spot on the miniature are virtually impossible to get in the Warner Bros. Studio Tour, so most of my references are actually from the corresponding set, and some of the details can vary between the sets and the miniatures. Anyway, the modeling process looked much like building the arches above, so I won’t bore you with too many in-progress shots:

I also discovered how good Blender’s denoising has gotten, which means I can drastically speed up my renders. My poor machine only chugged for 15 minutes or so on these images, rather than an hour or more.

Anyway, as I got to the very bottom of the tower, where it meets the courtyard, I started feeling the need for more data. So I went on another photogrammetry spree, trying to create meshes from every possible shot of the courtyard/clock tower set in the film. (There are a lot of them!) Accuracy and precision are very important to me with this project – partly just so I know I’m getting something close to the “real thing”, and partly because I know from past experience that small errors have a way accumulating. You estimate the height of object B on object A, and then you estimate the height of object C on object B, etc., and before you know it, lots of small inaccuracies begin to add up…and sooner or later, those will clash noticeably with other estimations elsewhere on the model.

I’d like to avoid that, which is why I ended up with over a dozen photogrammetry meshes (with different lighting and even different seasons) thrown together to get a more complete picture of the courtyard!

Ugly, yes, but very helpful as I prepare to complete the clock tower and start on the courtyard.

P.S. Don’t let me forget to finish the hospital wing.

P.P.S. Happy belated Mother’s Day!

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:

  1. The photogrammetry isn’t precise down to the millimeter – depending on the source images, the model can end up a little skewed.
  2. The technical drawings aren’t super precise either – for most areas, I don’t have detail drawings, only the overall floor plan.
  3. 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.

The Boathouse Steps Are Stupid

Ugh. I’ve indeed proceeded to the boathouse steps, and it turns out that they’re evil.

It all started out innocently enough. There are super detailed drawings available for the Deathly Hallows version, so I started there. I figured I’d work backward to the GOF/OOTP/HBP version, and then finally to the SS/COS/POA version. Above is the DH version in the process of being built, along with a newly wavy lake surface. Below is what they looked like when I was done:

Okay, so far, so good. It looks weird, but that’s just because they’re untextured, they don’t have any walls, and they don’t match up with the POA castle around it. The technical drawings were very explicit and internally consistent, so I felt very confident in this setup. Next up: the version from the middle three films! Should be easy, right? Just follow the floor plans, and then adjust the height to match the exact vertical distance between the boathouse floor and the viaduct courtyard floor, right?


It all went askew when I compared my steps to this angle of the HBP model at Warner Bros*:

See how the steps come right up to the bottom of the boathouse roof? Yeah…mine didn’t do that. They stopped noticeably lower. Something was off with the vertical scale. Presumably, some of the flights were supposed to be steeper than others. But it also occurred to me that my vertical measurements for the boathouse weren’t particularly precise either, so it was risky to try to get these disparate approximations to match up with each other.

No problem! Fortunately, this version of the castle has better photographic documentation than any other, since it’s open to the camera-wielding public. I was particularly enthused when I found this video – I knew Meshroom would like the camera motion, coverage, and image quality. So I fed a bunch of frames into the photogrammetry software and let it run. Actually, I let it run multiple times on different subsets of images – running everything all together resulted in some errors. Then I plopped all the different scans together into the same physical space:

Not exactly pretty, because this is a half-dozen scans with different lighting poking through each other haphazardly due to the limited precision of this method – plus lots of junk data floating around. (A lot of the stuff up top is the lighting fixtures from the Warner Bros. Studio Tour, haha.) Still, I figured this should provide some good reference, right?

Well…it turns out that the floor plans don’t quite match up with any of the scans. So that’s annoying. Again, it’s probably the result of the limited precision of this photogrammetry, but it makes it tough to trust this information.

And that’s really where I’m at right now…still trying to figure out the boathouse steps. I may end up needing to adjust the boathouse’s vertical scale, too. Oy…wish me luck.

* Apologies to the photographer for not giving credit. I’ve somehow lost wherever I found that image. If you recognize it as yours, please don’t hesitate to let me know!

3D Photogrammetry Scans of Universal’s Hogwarts

One of the ideas that struck me fairly early in this project is that it would be cool to compare the theme park versions of the castle to the “real” versions in the films. If you’ve ever walked through the Wizarding World of Harry Potter at Universal Studios in Orlando, Hollywood, or Japan, you know just how overwhelming it is to approach the towering facade of Hogwarts. Very effective theme park design.

Even so, much of the castle has been removed, the remaining sections have been modified, and the scale has been significantly reduced. (The filmmakers built their original Hogwarts miniature with a very specific real-world scale in mind.) The theme park version is highly evocative of the castle seen on the silver screen – specifically in Half-Blood Prince – but it’s still its own thing. (Three things, actually, since there are even slight differences between the versions at the three resorts.)

So…what would it look like to plop the Universal version down next to the cinematic version? That’s a question I intend to answer as the project progresses – hopefully with renders of them side by side! – but for now, you’re going to have to settle for these incomplete and very rough 3D scans of the Hollywood version.

These images are the fruit of photogrammetry, the science of extracting 3D measurements from photos. On a recent visit to Universal Studios Hollywood, I took about 400 photos of the castle. After heavily color-correcting these shots in Photoshop to bring out shadow detail, I threw them all into Meshroom, which dutifully set out to create a textured 3D model from the photos without any need for human assistance.

The first attempt failed. Unfortunate, but not surprising. There were angles I couldn’t capture due to the geography of the park and my own time constraints. (Not to mention the fact that we were trying to, you know, enjoy a day in the park!) Meshroom got confused and couldn’t connect all the disparate parts into one unified 3D model.

Not a problem. When I split the photos into six different sets that focused on smaller sections of the castle, Meshroom handled each set just fine on its own. Then I brought them together in Blender and manually lined them up with each other on top of an aerial photo. An HDRI sky added a bit of visual interest to the environment.

The scans needed a lot of manual cleanup, and even so, you can still see a lot of yucky fringes and artifacts, especially around the edges of each scan. That’s totally fine for my purposes…this is all just a rough guide for when I create my own model from scratch.

Still, interesting to look at, huh?

Getting Caught Up: The Hogwarts Project So Far

All right, let’s take a look at the project so far, since I’ve already been working on it for, like, a month before starting this blog.

First step was to gather as much information as possible: shots from the films, photos of the original Hogwarts miniature from the Warner Bros. Studio Tour, publicly available technical drawings of the miniature, behind-the-scenes footage, tourist photos and drone shots and floor plans of real-world filming locations…you name it.

Then came the important decision of where to start the 3D model – and which version to start with. Rather than jumping right in with super detailed final meshes, I blocked in a few basic shapes from the various films as a proof of concept in Blender. (My biggest concern was whether I had enough “vertical” information about the heights of various elements; I was pretty set on floor plans.)

Satisfied that this thing was actually going to work, I started over from scratch. The Prisoner of Azkaban version of the castle seemed like the best place to start.

Hey cool, it’s starting to look like Hogwarts!

Then something else occurred to me. I thought back to circa 2008, playing around with the now-defunct Photosynth service from Microsoft. You would feed it a series of photos of the same object or setting, taken from lots of different angles, and it would generate a 3D point cloud (with the original photos hanging in the space around it). I wondered if there was anything like that on the market today.

Turns out that photogrammetry freeware is a thing. I installed Meshroom and got my computer to start generating point clouds and meshes from moving shots of the castle. As you can see, these tend to be pretty rough; resolution, motion blur, lossy compression, dynamic range, and choices of angles are all limiting factors in terms of quality. But many shots still yielded data that I could use for reference in building the actual models.

Generating and refining these reference models takes lots of time and computing power, so this easily ate up at least a week in which I was doing no actual modeling. It was really one of my periodic returns to the information-gathering phase. In one Google detour, I stumbled upon some aerial footage of Alnwick Castle (one of the Hogwarts exterior filming locations for the first two films) and realized I could do more photogrammetry for that location, too.

Again, pretty rough. Nothing from these models is ever going to be directly included in the final project. They’re just a good way of collecting vertical measurements when no elevation drawings are available.

After spending so much time looking at shots of Alnwick, I felt compelled to start doing some actual modeling of those areas. I decided to start a separate model of Alnwick Castle itself; the plan is that I’ll eventually copy the appropriate segments over to the main model.

Lots of jumping around here; there are gaps in my references for certain areas, but I’m hoping to have more information soon. That last render – my most recent, from just this morning – gives a good sense for the level of detail I’d like to see in the entire model. (That part of Alnwick, the warder’s tower, was used as an archway leading toward the location of Hagrid’s hut in the first two films.)

Whew…that brings us up to speed on the current state of the project. Hopefully future posts will allow me to focus a little more on specific areas, since I won’t be summarizing a month’s worth of work all at once.

Like what you see? Got a question? Feel free to leave a comment. Otherwise, see you soon, I hope!