COS-OOTP Training Grounds Tower, Cont’d

Whew, sorry for the long delay…the months of sitting at my home desk have taken their toll on my arms, and I’ve had to significantly limit my computer use. This will be a shorter post as a result. I’m starting physical therapy soon…if you’re feeling particularly generous and you want to help support my recovery, my Venmo handle is @Joe-Cardello, for what it’s worth. 🙂

Anyway, let’s continue with the version of the training grounds tower that was seen throughout the middle of the Potter series, including Prisoner of Azkaban. As we work our way around to the west facade, my reference material becomes even scarcer, but I’ve got just enough to piece it together in a reasonably accurate way. I started with plain walls, deciding to add the windows and so forth later:

Here’s a view from overhead once I’d roughed in the main shape of the building. At this point, I wasn’t worried too much about cleaning up the intersections between walls and objects…I just wanted to make sure the layout made sense three-dimensionally:

You can see just a bit of the tiny courtyard in the middle. That’s one area for which I truly have zero reference (other than the basic floor plan). It roughly corresponds to the cobbled inner courtyard at Alnwick Castle, which was actually used in the location shoots for the first film, but the version in the miniature is much smaller and it has a different shape because of the way the Alnwick floor plan was reconfigured around it. So the layout of any doors, windows, or other decorative elements on that part of the miniature sadly remains a mystery.

As I said, I have less progress to share because of my ergonomic issues, not to mention the simple fact that this is a tricky structure to figure out. But I’ll at least fill out the rest of this post with an aerial overview of my POA castle so far:

Take care of your body, take care of your mind, and don’t be an ass to people who identify as transgender. See you soon!

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

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!

Starting the Training Grounds Tower

Holy crap! I can’t believe we’ve arrived at the final major tower of Hogwarts! I’ve been eager and afraid to tackle it because of its complex geometry and the limited reference available. Let’s jump in!

The training grounds tower was added to the original castle out of sheer necessity. Alnwick Castle was used as a major filming location so they needed it to be present in the miniature. Stuart Craig’s team tweaked its footprint a bit and built it up into a much taller complex of towers; the bottom floors just looked like Alnwick while the upper floors took their stylistic cues from the original castle’s other conical turrets. Evidently Mr. Craig didn’t like the vertical extensions, because they were totally redone for the second film in a style that slightly foreshadowed the more Gothic look that would take over in the third film. (Interestingly, some COS shots still feature the SS version.) That revision stuck around till Half-Blood Prince, when it was replaced with a single tower echoing the bell towers’ design.

Since I’m working on the Azkaban castle right now, it’s that second iteration of the tower that I’m focusing on. And “focus” is indeed the right word, because I’ve spent a lot of time just staring at reference images and…thinking. Trying to piece it all together. Eventually, I started working on the facade toward the right:

This is the project’s first render with the OptiX denoiser, which wasn’t compatible with my GPU till Blender 2.90. Denoising is critical with path tracers like the Cycles render engine, where speeding up the render introduces more noise. I was using Open Image Denoise before, but OptiX is faster and it’s retaining more detail, so I’m pretty stoked!

Anyway, training grounds tower. It’s proving as challenging as I feared/hoped it would be. The modeling itself is not particularly difficult, but the paucity of high-quality reference images makes it difficult to piece together all the details, especially since I want to get the scale right.

I’m keeping an eye on the original version too, since the lower section is identical and I want to make sure I can reuse it without any issues.

In a twist that will shock precisely zero longtime readers, I’m finding lots of small discrepancies between shots of miniatures, location shoots at Alnwick Castle, CG long shots, etc. As usual, I’m striving for something of a happy medium, but weighted toward the main 1/24th-scale miniature.

There’s still a lot more to do on this structure, but it’s been 10 days since I last shared my progress and I think I’ll save further progress for my next post.

The Domed Conservatory

I’ve been looking forward to this one! When the greenhouses went in for Chamber of Secrets, the small building forming the entrance to that courtyard was replaced with a larger and more ornate conservatory with a dome and cupola. It’s a neat structure, but my biggest reason for being excited is that there are blueprints at the Warner Bros. Studio Tour…and these provide lots of detail on the interior, which is hard to glimpse from the exterior of the model. The upshot is that today’s post concludes with the first (to my knowledge) views of the conservatory interior on the internet!

How’d I get there? Well, I decided to start from the inside; it’s easier that way, plus it allows interesting views that won’t be possible once the structure is enclosed. There’s an octagonal arrangement of planters and columns:

Texturing the interior is an interesting challenge. I don’t want to spend that long on it, since it’ll barely be visible from the outside. It’s also hard to find good texture reference precisely because it’s barely visible from the outside – and for the same reason, they probably didn’t go super realistic in terms of all the finishes anyway. (From what little we can see at the Studio Tour, it looks like the inside may have become understandably dusty, which further complicates things. I also don’t know what they were going for with the weird gold paint job on the planters.)

As I pondered this, I continued with the modeling. Next up was the spiral staircase up to the balcony level. An apparent inconsistency in the technical drawings gave me a moment of trouble with the number of risers, but I’m pretty sure my interpretation is the correct one. With a little sleuthing, I learned that this spiral staircase was based on a 1:25 scale set sold by E.M.A. Model Supplies in London. In fact, the specific product (ST-7304) is listed for sale on their website to this day. Here’s the product image:

They then added the cage and banister. Here’s my version with most of the staircase modeling done:

Finishing the staircase and moving on to the balcony above:

Unless you’re pretty short, you’ll want to watch your head as you ascend the spiral staircase. There’s a spot near the top with less than five feet of vertical clearance.

It looks like the foliage in the conservatory is mostly palm trees and the like; I tweaked some assets from CGTrader. These obviously won’t be an exact match to the ones inside the miniature, but they get the job done.

Time to start enclosing the thing:

The next section up has more dragons. I’d planned on simply using the exact same asset from the greenhouses…but I should have done my research first. Turns out the ones on the conservatory are a little different in shape/size. So I went back and roughly rigged the dragon so I could pose it a little differently for the conservatory. It’s not a perfect match to the pose, sadly, but it wouldn’t be worth it to do a whole ‘nother sculpt.

Then it was just a matter of adding the dome…

The only thing left was the cupola on top. But as I was about to start that, I randomly started noticing some issues with the castle’s overall coloration. The color has always been a tricky thing due to the various changes in the paint job, the lighting, and the color grading over time. But I’ve gradually found more and more unprocessed shots of the castle in relatively neutral white lighting, and comparing those to my renders, I decided my castle needed to be a little more yellow and a little less red. It’s surprisingly tough to get the right balance, so I’ll likely go back and continue to tweak the colors at some point. But for now, I think this brings us still closer to a convincing reproduction of the castle:

Anyway, let’s finish the conservatory!

Not half bad! But of course, the real fun is putting the camera inside, where – again, to my knowledge – no Potter fan has gone before! It’s a relatively tight interior space, so we’ll use a fisheye lens:

And here’s a shot from the balcony level:

You saw it here first, folks! (And if you didn’t…well, let me know where you did see it first, because I’d love to see more views inside the conservatory!)

I think my next steps will be to finish the last bit of the curtain wall surrounding the greenhouses and then finish up all the footpaths and lawns. See you soon!

You Can Never Have Too Many Greenhouses

The 3D model of the Prisoner of Azkaban castle keeps chugging along! After completing that first greenhouse, I duplicated it three more times:

These four all share the exact same design, but then there are four more along the east side of the Durham area, and their dimensions are a little different, so I had to create (and thrice duplicate) a new variation over there:

And then at last there is Greenhouse Three, which is a smaller lean-to on the castle’s outer wall. (You can catch a glimpse of it in the above render.) This is the greenhouse where the Herbology lesson with the mandrakes takes place. It’s got its own unique design, so I took care of that next. Some of the dimensions here don’t line up quite as precisely as I’d like, but I’ve tried to minimize the number (and visibility) of compromises as much as I can:

You can also see that I’ve also added rust, adjusted the weathering of the wood, and started with the footpaths between the greenhouses. I even threw in one of the largest vines that snakes its way out of the greenhouses, visible toward the bottom right:

In the background, you’ll see that I’ve begun the curtain walls around the greenhouse area. These were actually there in the original design of the castle, even before the greenhouses were added in Chamber of Secrets; they just had to be pushed outward a bit to accommodate that addition. Here’s a better view of their progress:

See where the wall stops on the right? That’s going to be the site of the final greenhouse structure, the domed conservatory that also acts as the only way out of the greenhouse courtyard and into the grounds. But I’m going to save that for the next post. I’m hoping to even share something I’ve never seen before: an interior view of that conservatory*!

In the meantime, I’ll leave you with a slightly different aerial view of the POA model so far. Still plenty more to be done, but we’re getting closer!

* If they happened to include the conservatory interior in any of the video games, let me know! I haven’t played them but I’ve looked through longplays on YouTube and never spotted it.

Starting the Greenhouses

Hogwarts got its greenhouses added in Chamber of Secrets. They sat undisturbed in what was formerly an open courtyard until Deathly Hallows Part 2, at which point some adjacent architecture was removed and the greenhouses expanded a bit to fill the empty space.

My own 3D recreations of these greenhouses provided some fun challenges right off the bat. As I alluded to in the previous post, I was surprised to realize that they are not all identical. I mean, I knew that there was a lean-to attached to the wall of the castle as well as a domed conservatory out front, but I’d assumed the other greenhouses were octuplets. No such luck. The ones that run parallel to the Long Gallery aren’t quite as long as the ones that run east-west along the north facade, though they’re made of the same basic building blocks.

As always, I wanted to get the details and dimensions right. Without much in the way of detailed technical drawings, I resorted to making some quick-‘n’-messy diagrams to organize my thoughts and measurements.

Quick and messy, like I said, but it really helped me figure out how to proceed with the modeling. I started framing just one wall of just one greenhouse, laying out the largest support posts every 10 feet. Some of these will eventually have sculpted dragons on top, but those’ll come in a future blog post:

Blender’s Array modifier makes it easy to just work on one segment and have all the others update accordingly. No textures at this point either – I knew the white paint would later need to be scuffed up a bit.

Adding more details, temporarily pretending that the greenhouses don’t have any doors:

The familiar question of whether to follow the miniature or the set cropped up yet again. Actually, it’s more complicated. The greenhouses didn’t show up often in the films, but they got a glorious establishing shot in Chamber of Secrets. The VFX team put together a very impressive shot that moves across the lake, over the grounds, and right through an open window into the lean-to, AKA Greenhouse Three. The shot combines the 1/24th-scale Hogwarts miniature (and CG background) with a live-action plate shot on the greenhouse set, and it’s pretty seamless, especially for the early 2000s. But the camera has to go right up to the greenhouses, exposing a lot of detail…and at 1/24th scale, some of that detail wasn’t going to hold up. So they built separate 1/8th-scale miniatures of the three greenhouses the camera would get closest to. For whatever reason, while those larger bespoke miniatures match the design of the set, the main castle miniature is slightly different. I’m mainly talking about the windowpanes – they’re narrower and more numerous in the main castle miniature.

Sooooo…what to do? Follow the set and 1/8th-scale miniature, or follow the 1/24th-scale miniature? I take these decisions on a case-by-case basis, and for the greenhouses, I ultimately went with the wider windowpanes from the set and 1/8th-scale miniature (for a variety of reasons).

Here we go – doors and details and preliminary materials.

Starting to add the beams for the roof:

Hey, it looks kinda like a greenhouse!

By this point, I had been really debating exactly how much interior detail to do. This project file just keeps getting bigger and bigger, which means my computer has an increasingly hard time keeping up. It’s thus in my best interest to only include the details I need – but of course, the greenhouses are rather transparent, and I still wanted to them to “read” correctly from the outside. Once I had them fully enclosed, I was able to see how the materials interacted with the light and decide how much interior detail I needed to include. Not much, it turns out, as long as I don’t let the glass get too crystal-clear:

Some of the geometry got slightly messy as I went around the corners of the greenhouse, trying to respect all the various reference images as much as possible, but I’m pretty happy with the result:

For a moment, I thought all I had left to do was sculpt the decorative dragons on top, but then I remembered that I needed to pop the roof hatches too – otherwise, how would the camera float in for that great shot in COS?

(These are all open at random angles, BTW…I’m anal, but not anal enough to match them exactly.)

Anyway, I’ll be sculpting the dragons next, but we’ll save that for a future post, hopefully in video form. I’ll also need to create all the other greenhouses using the same components. See you next time!

Finishing the Bell Towers – “Azkaban” AND Original Versions!

Here we go – those bell towers need to be completed. I finished the intricate openings and decorative motifs in the middle parts of the towers. Fortunately, these never changed in any of the films, even when the tops of the towers changed, so I only had to create them this once!

Then, to complete the bell towers, I added the tops of the towers, which are very similar to the top of the central tower – just shrunk by about 23%, and with a few minor design differences. I was grateful for this not only because it allowed me to reuse elements from the central tower, but also because I discovered a mistake in the central tower in the process. All fixed now!

Of course, there are two versions of the bell towers: the original design, and this Prisoner of Azkaban redesign. With the latter complete, I decided to switch over and do the former as well!

Sadly, photogrammetry is no help when it comes to the original tops of the bell towers, but their simple design is pretty easy to eyeball. A few of the smallest details were educated guesses – for instance, I’ve added windowpanes in a few areas that could just be openings.

Anyway, enough talk – let’s compare the two designs! Drag the slider below to compare the original Sorcerer’s Stone design (left) to the Prisoner of Azkaban redesign (right). (The smaller tower above the Long Gallery will also come and go, since that was added in Chamber of Secrets.)

Here’s a reverse angle:

Surprise – there’s the original design of the central tower, too! I snuck that in there as well.

Viewing the whole castle from lake level, you can really see what a difference this simple redesign of these three towers made in the castle’s overall silhouette and character. My model is also looking a lot more complete overall!

Adding the wall between the bell towers was easy, since all of its elements are similar to stuff I’ve already created. I briefly considered tackling the greenhouses next, but then I got distracted by the adjacent walls that bring us to the training grounds tower and the middle courtyard, which will probably be where I go in our next blog post.

In the meantime, Ms. Rowling continues to tweet disappointingly misguided things about transgender people. For what it’s worth – if you, dear reader, happen to be trans, non-binary, or a member of any other oft-marginalized community, know that this Hogwarts (incomplete though it may be) will always be there to welcome your awesome self, and so will I.

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!

Modeling Time-lapse: Durham Transept & POA Central Tower

Something different today! By request, I’ve documented my 3D modeling process with a sped-up screen capture. (You’re welcome, Pete!) Watch me work on the area that corresponds to the transepts of Durham Cathedral, as well as the Prisoner of Azkaban version of the central tower. I’ve tried to keep the commentary relevant no matter whether you’re a fellow Blender user or not.

If you’re interested in more videos like this, comment here or on the video to let me know! They take some extra work but I can do more if there’s enough demand. Don’t forget to subscribe to the YouTube channel too!

Here are a few renders of the progress seen in the video. As always, click for larger versions:

After finishing the video, I put the last few touches on the central tower:

Fits in pretty well, no?

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.