Complete in 3D: Gryffindor Tower (POA Version) and the Dark Tower!

The rest of the work on the Prisoner of Azkaban version of Gryffindor Tower proved pretty easy. The remaining windows came together quickly.

I even added this mysterious pipe-like thing that juts out directly over Harry’s window (near the top middle of this render). No idea what it is…it’s been there at least since Goblet of Fire, probably since Azkaban or earlier, and it’s still visible to this day in the main VFX miniature at the Warner Bros. Studio Tour in London. If you happen to have any idea what it is, be sure to leave a comment!

You also can see I removed the suspension bridge at the lower left. It’s not completely deleted, just moved to a hidden layer; it needed some reworking that I just don’t want to deal with at the moment. It’ll come back eventually.

Work then moved on to the Dark Tower. Whereas Gryffindor Tower was just revised a bit for the third film (mainly making it taller), the Dark Tower was an entirely new addition. Its purpose was to provide a visually dramatic location for Sirius Black’s cell at the end of the film. It sits roughly where the real-world Durham Cathedral chapter house structure sat in the first two films.

The basic structure of the tower is super simple – just a slightly tapered cylinder with an off-center pyramidal base. Sirius’s cell is perched right on top; the render above shows the front wall of the cell beginning to take shape. I kept going and eventually finished all the detail on the top of the tower.

The most interesting challenge ended up being those four stone gargoyles near the top of the tower. These are never seen up close in the films…they pretty much just look like vague oblong shapes with a skinnier protrusion at the end. But I started doing some digging in the various video games released around this time, and I found some much closer shots. To my surprise, the games reveal a design that looks more like a vulture than anything. Now, the games obviously use 3D assets built specifically for the games, and the design can totally change in the process of translation from film to game. But these closer shots seemed consistent with the blurry shapes visible in the films, so I decided to just go for it. They gave me some fun practice with sculpting and retopologizing.

The rest of the tower really doesn’t have much more detail on it, so I’m calling it finished! Here’s a render showing the completed tower with the rest of the model so far. ~~Fun fact – Harry’s window actually looks pretty much straight at the tower where his godfather ends up being briefly held. That’s kinda sweet.~~ Whoops, this isn’t true – the Defense Against the Dark Arts tower totally blocks the view of the Dark Tower from his window. Never mind!

I’m planning on starting what fans have been calling the Defense Against the Dark Arts tower next. See you soon!

3D Gryffindor Tower; or, Harry Potter and the Cursed Corbels

In the last week, I got fed up with some parts of the Prisoner of AzkabanHogwarts exterior near the suspension bridge that I really can’t find much information on. So I decided to switch gears and add more detail to Gryffindor Tower – in particular, I wanted to create the corbels that support the top part of the tower, where the boys’ dormitory is.

It turns out this is tougher than I expected, and it turns out explaining why is pretty tough as well. It has to do with the way the corbels shrink inward (or don’t) toward the center of the tower, and the way they extend all the way out to become part of the circular shape of the tower, and the way they have semicircular notches carved out between them. You can see a few examples of these designs in this shot from Sorcerer’s Stone, although Gryffindor Tower itself isn’t visible here.

This became quite a roadblock. Every time I thought I had it, Blender would spit out results that looked wildly wrong. So damn frustrating. So I did what any responsible adult would do: I threw up my hands and switched over to something completely different, a music project I’d been working on prior to the Hogwarts project.

As a result, I spent the last few days not thinking about polygons or Array modifiers or enchanted Scottish castles, and it turned out that this did a world of good…when a piece of missing hardware stalled my music project, I reluctantly decided to give the corbels another shot. And whaddaya know? I figured them out pretty quickly!

It took a mixture of Array and Screw modifiers on different objects combined with Boolean operations in a specific order. The results aren’t anything insanely spectacular to look at, but they’re decently accurate, and I should be able to use similar techniques elsewhere on the castle. (Ignore the vertical banding on the tower, by the way; you’ll sometimes see this in curved areas I haven’t yet bothered to smooth out.)

One interesting challenge with this tower is that some of the details actually change from shot to shot in a given film. The reason is simple: some of the visual effects shots in the films are actually composites of multiple miniatures on different scales. The main castle miniature was built at 1:24 scale, which is great from a distance. But for closeup shots, the team built larger versions of specific sections of the castle and composited them in with the main model. For instance, this VFX shot of Gryffindor Tower from Goblet of Fire is nicely broken down in a video at the Warner Bros. Studio Tour in London. The first image here shows a smaller model with part of the tower removed; the second image shows what it looks like when the larger, more detailed miniature of the tower is composited in, allowing for quite a close shot.

This wouldn’t pose any issues for my model, except that it turns out there are actual design differences between the different miniatures in some cases. For Gryffindor Tower, I was specifically noticing the cornice around the base of the conical roof. It has a decorative sort of double curve to it here, right? Well, compare it to the main miniature in this photo from the aforementioned Studio Tour:

The cornice is much simpler and flatter. I’ve spotted a few other spots that change like this. So that raises the question…which version do I create? So far, I’m mostly opting for the most detailed versions I can find; notice that my render above includes the more detailed version of the cornice. But I’ve got to admit, it feels weird to built something that doesn’t fit with the design of the main model. (That’s another reason the suspension bridge is tricky, incidentally…its design actually changes depending on whether we’re looking at the main model or a closeup.)

Anyway, I gotta go build some more castle windows. More updates soon!

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?

Hogwarts 4D Progress: “Azkaban” Suspension Bridge Takes Shape

One thing about me is that I don’t like to stick to any one part of a personal project for too long. So sure enough, I’ve put the Alnwick model on hold as I’ve jumped back to the Prisoner of Azkaban version of the castle.

At the moment I’m mainly focusing on an area of the castle that’s not very visible in the films. On a basic level, the castle (not counting any outbuildings, etc.) consists of two separate buildings that are attached by a few bridges over a deep, narrow ravine. The northern building is modeled largely after Durham Cathedral while the southern building includes the rather more unique designs of the Great Hall and Turris Magnus (the tall, steep tower with Dumbledore’s office near the top). It’s the southern building that I’m working on at the moment…but I’m focusing on the northern facade, the one that faces the other building. The filmmakers didn’t have many reasons to send their cameras through that area…but that doesn’t mean I can’t!

Obviously there aren’t any textures here, but this is another example of an area that’s approaching final levels of detail. The last few renders are especially cool to me because they’re from angles that would be impossible in the “real world” – the camera would be underground, or inside the northern block.

Some of my most proud moments since the last post have included sculpting a bas-relief Hogwarts crest (seen on the white square near the top of the last render above) and figuring out the Turris Magnus spire, whose shape smoothly blends from a hexadecagon (16 sides) to a circle near the base. I also like the suspension bridge, one of three footpaths between the two blocks of the castle. (Its biggest moment in the films is in Goblet of Fire, when the dragon chases Harry right through/past it…but that shot is over in, like, a second.)

Ooh, as an added bonus, here’s a fully navigable version of the model via Sketchfab. There are some numbered annotations that point out landmarks. I don’t plan on uploading one of these for every single future post, but I’ll try to do it from time to time so you can go exploring.

Have fun!

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!

The Beginning

All my life, I’ve often found myself tumbling headlong into unusual obsessive hobbies. In January 2019, I tumbled into a new one. I was struck by the realization that Hogwarts Castle underwent a number of design changes over the course of the Harry Potter films, and I wanted to be able to watch a time-lapse of those changes from a stationary vantage point. Any stationary vantage point. The only solution was to create a 3D model…of all 7+ versions of Hogwarts…in my free time.

So I got started.

I have no idea how long this passion project will go for – I do tend to jump between my different interests quite a bit – but it’s been a good time so far, and I thought I’d share my progress with any likeminded fans of the Potter franchise, cool architecture, and/or 3D modeling.

Have fun perusing!