Rescaled Bricks & Greenhouse Dragons

I promise we’re going to get to sculpting the decorative dragons from the tops of the greenhouses, but first I wanted to share a “before and after”. A reader who goes by kronkolweg pointed out that my castle’s bricks were a little big. It had already been starting to bug me a bit, and this was just the kick I needed to get off my butt and fix it.

For the original castle miniature, one or more brick textures were hand-sculpted, molded, mass-produced in FastCast resin, and glued to the miniature’s wooden understructure before being hand-painted. There was a transition to more detailed plaster-based textures starting in Chamber of Secrets – I’m not sure if any of the original resin brick textures ultimately survived through to the final Half-Blood Prince iteration of the miniature. In any case, the overall effect is the same, and my procedural brick material mimics it without requiring me to individually texture each wall. The thing is, when I created this material (as documented here, here, and here), I had much less of the castle built, which meant I had fewer points of comparison for the scale of the bricks. Frankly, I don’t remember how much actual measurement there was, as opposed to simple eyeballing, but it’s become clear that the results are a little oversized.

So, being the Excel nut that I am, I sat down and made a spreadsheet. I took horizontal and vertical brick counts for various areas of the castle, comparing my model to the miniature. There’s a certain margin of error in the scale of my castle, and the bricks of the miniature are not necessarily of completely uniform scale, so I averaged the different measurements and arrived at my brick adjustments: a 34% reduction in width and a 21% reduction in height.

The interactive sliders below compare the old larger bricks (left) to the new smaller bricks (right):

The difference is subtle from any real distance, but it’s more accurate now, which always feels good.

With this tweak completed, I shifted my attention to those greenhouse dragons! Fortunately, they’re all identical, so I only had to sculpt one. I did so in a separate file, and – well, if you’re interested, just watch part 1 of the video.

Frankly, I can’t get enough of these sliders, so let’s compare the base mesh to the full-resolution sculpt…

…and now comparing the full-resolution sculpt to the retopologized version with normal mapped details:

If the differences seem really minor…good! The point of retopo is to vastly simplify the geometry, which makes the asset a lot more manageable. The sculpt on the left has over 1.3 million faces; the retopologized version on the right only has around 1,500. Much easier on the computer! Of course, that eliminates a lot of details; baking and applying a normal map is a way of faking those back in, hopefully with an end result that’s nearly indistinguishable from the original sculpt. (In this particular case, there are a few small artifacts in the shading, but these are not noticeable when color is applied and we move the camera away a little.)

You can watch this whole process in part 2 of the video:

The retopology process is still a lot slower, harder, and more frustrating for me than I’d like, but in the end I was satisfied with the result, so I created an appropriate material, brought the mesh over into the main castle model, and duplicated it to the appropriate spots on the single greenhouse I’d already created. Voilà!

That’s a wrap for the dragon, and for this greenhouse overall! The next steps will be to duplicate this greenhouse and create the other two design variations on it. Then I’ll be able to move on to the domed conservatory, the curtain walls surrounding the greenhouses, and hopefully some ground cover and footpaths. Be sure to subscribe to this blog and the YouTube channel for updates as they come!

More POA Hogwarts Texturing

Well, so much for turning the materials off and focusing on the modeling again! The process of creating and tweaking and refining these textures has become a bit addictive.

Here I’ve created a shingle texture for the roofs and spires. The finials have also received a copper patina treatment to match what we see in the films. (Again, no image textures here – all procedural.) Less obvious are some subtle adjustments to the brick texture. Notice how the bricks no longer appear to be all perfectly flush with each other – some stick out slightly further, like you’d see in real medieval construction. There were still more tweaks needed, though. In particular, I wanted more vertical streaks to mimic dirt deposits from years of rain and weather. Those are quite noticeable on the “real thing.” Many hours later…

…that’s more like it! Still not perfect, but I don’t think I’ll be able to convince current versions of Blender to do any more on their own. I could paint the streaks in myself, but I’m still really trying to stay procedural so that when I build the rest of the castle, the brickwork and weathering and dirt patterns will all just magically appear without any further work. (Unrelated, but you can also see a few contour lines down near the shoreline. Once these are completed, they’ll act as a guide for me to sculpt the landscape the castle sits on.)

If it’s been a while since you’ve seen the first couple of Harry Potter films, you might be thinking that this castle looks awful colorful. Were the bricks really that red, the roofs really that bluish? Well…yes, at first. The Hogwarts we see in Sorcerer’s Stone and Chamber of Secrets has pretty saturated colors. Here’s a frame from the latter, for instance:

It was really only once we got to Prisoner of Azkaban that the colors took a turn for the grayish green. At least part of it was just color grading on the film; it’s hard to tell if the miniature itself received a cooler paint job, but if it did, it wasn’t as dramatic a difference as it appears in the film:

That’s more or less the color scheme we see through the rest of the series, and the theme park versions at the various Universal resorts don’t stray far from this look. So despite my original intention to just get the original look of the model, I created an alternate coloration for the model, too:

It’s still not as green as what we often see after the first couple films, but it’s at least closer. I set up the material nodes in Blender so I can quickly switch between color schemes across the whole model; I suppose I’ll probably stick with this coloration while I continue work on the POA version, but the more colorful version will be ready to go when I start working on the castles of the first two films.

I’ll round out this post with kind of a cool, different shot of the castle in silhouette. You can see I’ve finished the windows on the Defense Against the Dark Arts tower, although I discovered a small mistake in the lowest row of windows after this render was made. Unfortunately, this angle also highlights some of the areas where the bricks don’t map quite right onto the forms of the castle. After a lot of experimenting, I’m starting to think this may be as good as the mapping is going to get. But who knows?