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!

Baking the Bird

When we last visited the statue of a certain golden eagle gobbling up a certain rattlesnake from a certain courtyard in the third Harry Potter film, I’d created a base mesh for the initial sculpt in a separate file…

…but I’d temporarily given up when the flight feathers proved more challenging than I’d expected. Although I didn’t share this last time, I’d actually gotten the head off to a decent start, especially for an artist who doesn’t do much sculpting:

But those dang wings were confounding me. Sculpting them was giving results that were messy and uneven, so I decided to try modeling each feather as its own mesh. This seemed more promising, but I still couldn’t get the feathers to “flow” nicely. They have a lovely sweeping three-dimensional curve to them in the film and I wanted to capture that.

After taking a few days off to stew over this frustrating problem, the right method became apparent. I created four different feather shapes/rotations/positions (absolute shape keys, for my fellow Blenderheads) and allowed Blender to…well, blend between them. After playing with them for a while, I finally arrived at a result I could feel good about:

I’m sure there’s an ornithologist somewhere out there having a heart attack over the anatomical tomfoolery on display here, but whatevs. At a certain point, I have to remind myself that this statue is just a tiny part of a much larger just-for-fun model – and only certain versions thereof, at that. It’s not lost on me that I’m putting more effort into this statue than is really necessary for the purposes of this project, but I view it as an opportunity to learn and practice organic modeling skills that I’ve tended to neglect.

Anyway, I began creating some basic materials and threw in a background HDRI for lighting. The same shape key technique worked for the tail feathers…

…but not for the finer, more textural plumage on the body. So I used Materialize (another piece of freeware) to help me create a textured sculpting brush from photography of real eagle feathers. Back in Blender, I used this brush to directionally “paint” three-dimensional feathers along the body. This gave me a great base texture; I reshaped parts of it by hand to create more convincing layers of feathers. Should be good enough, considering that this will mostly be seen from further distances.

I thought the legs and feet were going to be hard, but they actually turned out to be a lot of fun:

This brought the sculpt of the golden eagle to a state of completion! But at this point, this was all still real geometry – millions of tiny flat triangles connected together to form a complex, bumpy surface that slowed my computer down quite a bit. That’s where normal maps come in. I retopologized the statue into a nice, simple, clean mesh*…

…and then I baked all the details from the original sculpt into a normal map, an image that simulates the shading of the original detailed sculpt on the new simplified mesh. The result looks virtually identical, but the simplified model is waaaaaay less sluggish in terms of software performance, render times, and animatibility. (Shut up, I’ve decided it’s a word now.)

Next steps: creating the rattlesnake, posing the eagle to hold it, integrating the whole statue into the main model, and damaging the fountain to match its dilapidated state in the film. But I’ll save all that for another post. In the meantime, I’m just glad I decided to spend the extra time on this. Confession: I’d never actually done a full-on organic model like this, start to finish, from base mesh to sculpting to retopo and normal baking. It’s really boosted my confidence!

On a more serious note, I’m sure the recent months, weeks, and days have been very difficult for a lot of you. Sending lots of love, with the hopes that we will live to see – and create – a better tomorrow together.

* I’m not an expert in topology and edge flow…if you are, I very much welcome your critique! I’m sure I overcomplicated parts of this mesh, and there were a couple of hidden areas where I decided to just cut my losses and learn from my mistakes next time. The wings feature some staggeringly bad topology – spiral loops, super-squashed quads, and even a lone triangle – but I didn’t care much because these are almost entirely hidden by the feathers. They don’t even have any detail sculpted on them.