Full Speed, A Head!

 Posted by at 18:49  No Responses »
Jan 102017
 

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Hey, remember this project? This project that I haven’t much talked about in the last, oh, nine months or so? Guess what! I just finished assembling the high-detail paper model for the base mold!

Full-resolution paper model mold base, front 3/4 Full-resolution paper model mold base, rear 3/4

I did indeed switch to using hot glue after my last update, to excellent effect. Rather than applying it via a hot glue gun, I instead used the glue gun to keep the glue in a liquid state and spot-applied it with toothpicks. This worked out really well, with one giant downside that I didn’t recognize until the damage had been done: leaving hot glue to just sit there with heat on it results in some of it vaporizing. My office, where I’ve been assembling this, is not well-ventilated. As a result, once I realized why I had started coughing and feeling miserable, I shelved the project for a bit. Also, finishing Embers and running a D&D game for some friends took over my life for a little while, but Embers is now out1 and I’m finally getting a handle on balancing my prep work for the D&D game, which means time to work on this has materialized once more!

Full-resolution paper model mold base, front 3/4 No doubt spurred into action by seeing Rogue One, I dove head-first back to work. This time, I kept a fan running at all times and wore a simple dust mask, which prevented most of the fumes from getting anywhere near me. I also purchased the fellow pictured here on clearance at Target to keep me company while I worked.

Everything has come together exceedingly well, as far as I’m concerned. I hit on the idea of creating small little cardboard cross-section supports, hearkening back to my original design approach to this whole project. I noticed some structural deformation happening to the cardstock due to the growing weight of the model. Given that forestalling this kind of warping with the resin and fiberglass step is the next part of the plan, I didn’t want to go into that step with an already-warped model!

Cross section printout glued to flat cardboard
Cardboard cross-section supports on the face Cardboard cross-section supports on the scalp and brim

I looked over the major distortion points and created simple planes intersecting the helmet model in Blender, then printed these out with the paper model plugin the same way I had everything else so far. I rummaged around in the basement for a cardboard box of the approximate right dimensions and sturdiness and then got to work slicing these up and gluing them into place. I used a green marker to identify the vertex attachment points on the physical model that corresponded with the origin locations for the planes on the 3D model. Turned out as well as I hoped!

Here’s the completed helmet beside its prototype ancestors. The massive size of the original prototype doesn’t really come across in this picture due to perspective, but it dwarfs both the small sizing prototype and the full-resolution model.

Full-resolution paper model alongside low-resolution prototypes.

With ventilation now prominent in my mind and knowing that my next step involves resin and fiberglass, I need to resolve the workspace air quality issue. It’s the middle of winter, so working outside just isn’t an option. Fortunately, I have a solution that’s been waiting for me to realize it exists for over seven years: the small, unused, vaguely creepy basement side room beneath the sun room. I can’t realistically ventilate the entire house-length basement to the degree I’d need to for working with resin, but that little room is its own space with its own window. Getting enough airflow to keep it well-circulated is easily within reach of a hardware store ventilation fan and some dryer vent tubing to direct the fan’s airflow out the window.

Making those modifications to this proto-workshop is my next step. I’ve also started formulating concrete plans for the vacuform table I want to build to manufacture the rest of the armor, which I’ll try to post more about in the coming days and weeks.

  1. And the next book’s word count is increasing day by day, don’t worry! [↩]

The Face Of The Future

 Posted by at 01:03  No Responses »
Mar 152016
 

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Been quiet on the stormtrooper front of late, but it’s still coming along!

Face plate as of March 12 Full face and forehead as of March 15

Still all done with tape, with a few exceptions where I resorted to superglue (and nearly stuck my fingers together several times). I’m thinking about trying hot glue as an alternative. Still sets quickly, but is a little more forgiving. Messy, though…

A New Level Of Detail

 Posted by at 23:55  No Responses »
Oct 262015
 

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I may have gone a little overboard with how detailed the paper printout of this model is. That said, it’s going to look amazing when it’s done.

The mic tip inset

I’ve been assembling everything with nothing but scotch tape so far. Cutting up tiny strips of tape and putting enough pressure on them to make sure they stay in place is proving incredibly tedious, though, and I’m mulling over various glue solutions. (Elmer’s? Superglue? Something else?)

Pieces under construction

Even so, when I can put it beside my two prototypes and see just how much better it is, it’s worth the effort.

Comparison with the prototypes

The Sizing Prototype

 Posted by at 21:31  No Responses »
Oct 152015
 

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Satisfied with my revised model and with scale issues now addressed, I decided to make one more prototype before printing out a high-resolution paper model that will go on to form the basis of my helmet mold. This one would be very low resolution, its only purpose to validate that it was big enough for my head and that my proportions were vaguely correct.

The smaller sizing prototype next to the first prototype The smaller sizing prototype next to the first prototype

As it turned out, this actually went a little too small, due in part to compensating for the size correction in the 3D model, but not the printout. Fortunately, it means the next round should be bang-on. I also acquired some fiberglass mat and resin with which to reinforce the paper model prior to slathering it with Bondo, which is heavy. I don’t want the paper to deform under the weight, so the fiberglass-and-resin step aims to give it enough rigidity to prevent that. The original large prototype is shiny in these pictures because it’s been given an initial outer coat of resin. The fiberglass will go inside for structural strength.

I, uh, also couldn’t resist checking the sizing prototype’s fit…

Imperial Derptrooper

Adventures in Camera Calibration and Photo Modeling

 Posted by at 00:19  No Responses »
Sep 112015
 

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Photogrammetry has been a major interest of mine for a number of years now, but all of my efforts toward making use of it as an artistic tool have thus far met with failure. None of the open-source, free, or even pay solutions either work or do what I want.1 I have designs on cooking up a program of my own at some point that does it all, but haven’t really set aside the time (hah!) to work something up.

Imagine my delight when I discovered that Blender could do some of what I wanted, natively.

It’s got major restrictions, though: namely, it only solves for a single camera (i.e. one focal length, one sensor size). Mingling images from different cameras, even if the various properies of those images are known2, is a no-go. That put me in a bit of a pickle, because I have a ton of Stormtrooper helmet reference photos, but very few from the same camera and even fewer that present a good “turntable” set. Fortunately, I did have one set, complete with full EXIF data that I could use to set the correct camera properties!

Of course, it was only nine images, with a lot of movement between frames. Blender couldn’t hope to solve that on its own. So, I spent hours and hours every night tracking points across my nine “frames” by hand, trying to find any features that stood out and were easily tracked. Naturally — because it couldn’t possibly be easy! — these points were almost never major “feature” points of the Stormtrooper helmet as one might conceive of them. They were usually blemishes; chipped paint, drips, dings, and so forth.

It took me a while to realize that tracking these “defects” was even worthwhile. My first approach was to try to project the 3D coordinates into the scene so that they coincided with actual features of my existing model. As time went on and I learned more, though, I realized this was folly. I just needed the right “origin” (I used the top of the gray “frown”) and to set the proper scale. I also came to understand, since I wasn’t defining any lines as denoting an X and Y axis3, that the camera solver made use of my initial camera position in 3D space as-is. It wasn’t “solving” that; it was using that as the starting point for the camera’s motion. That meant I had to eyeball that into the right position.

Eventually, though, I got it. A “perfect” solve is anything with a Blender-reported error of <= 0.3, Anything up to about 6 can still be "pretty good." My solve is ~0.9, which I am astonished by after how impossible a task it seemed when I set out.


The little balls are the 3D projections of my tracking points. The reason the photo and the right side (camera left) of the model are so different is explained further down. Image source.

With my camera calibrated, I could finally start modifying my existing model to make it better match the real, screen-used prop! This was the very first time in my entire history 3D modeling that I’ve been able to do that — take a “real life” picture that wasn’t purpose-shot as near-orthographic and use it as a reference plate in 3D space. It took some doing, but this part was much easier than the tracking itself. After all, it’s essentially the same sort of thing I’ve been doing for the better part of two decades. It entailed a great deal of hopping back and forth between “frames” to make sure everything lined up from all nine of my camera angles, but eventually I had the entire left half of the helmet photo-matched.

The screen helmet, though, is asymmetrical. That meant copying my left-side model and tweaking it all over again on the right side to make it match that one. That went a great deal faster, though, and with a quick hop back over to the left to do some final tweaks, I had a bang-on (with a handful of exceptions that could easily be chalked up to lens distortion of the photos themselves) match for the asymmetrical ANH Stunt helmet.

From there, it was a simple matter to “average” the vertices from the left and right sides to create a symmetrical helmet that matched pretty well with both the left and right helmet sides in the photos.


(Click for full-resoltion)

Next step, convert it to paper!

  1. PPT and Voodoo always seem to crash or spit out garbage and Catch123D is super off-putting. The Cloud and cloud computing can be amazing things, but I still want my applications local, man. [↩]
  2. One of the things that’s possible to do in general, given sufficient shared coordinates between images, but unknown camera parameters, is to back-calculate the camera properties. My photogrammetry program, whenever I eventually write it, will do this. [↩]
  3. My image sequence was shot against a single, static background and the helmet itself was turned, so there was no true 3D origin coordinate I could use. [↩]

Full Guinea Pig

 Posted by at 20:36  No Responses »
Aug 202015
 

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This is sitting on my dining room table right now.

Glaring inaccuracies? You bet. Beyond the overall dimension one I mentioned yesterday, even. All correctable in the next version, which can also be even more detailed on top of being more accurate.

I’m…pretty excited.

That excitement, though, is tempered somewhat by questions and self-doubt around the term “accuracy.” Ever since hearing about them and especially since meeting some of them in person, I’ve had my eye on eventually applying to join the 501st, whenever I got myself around to actually building this damn thing. But even though that badge of honor, that community would have meaning for me, doing this my way has more.

I don’t aim to achieve “screen accuracy.” The screen accurate model is asymmetrical, there are differences in the helmets seen in each movie, and even within individual movies (the ANH “hero” and “stunt” helmets). For my helmet, I want to opt for the “best” of all of them, not just pick one and replicate it. That’s not to say I’m looking to take shortcuts or produce a sub-par product by any stretch of the imagination. My goal is to create something that you could easily put on screen next to any of the other “screen accurate” suits and have it blend right in…unless you knew exactly what to look for.

I’ve been lurking on the 501st boards for a long time and the prevailing sentiments on this topic stick to just a few schools of thought.

There is the most common reaction that one should “just buy a kit” from an approved vendor. Some consider this the “cheapest” path, especially factoring time in. Maybe they’re right, if that’s where their priorities lie. I want to create, so that holds no value to me. Others expressing this view come across as pushing a marketing scheme. “You won’t get approval to join unless you buy from an approve vendor!” I realize this is an intensely cynical view; the “approved vendors” have all spent tremendous time, thought, and energy into creating authentic, accurate replicas and that is work that should only ever be commended. It’s still got an unpleasant feel to me that I can’t shake.

There are those who simply don’t “get” the process of papercraft molds. They see the papercraft version and think people are going to apply with that alone, which obviously doesn’t meet any kind of standard for authenticity. And, for what it’s worth, some — many, even — folks do go on to use the paper model as the basis for the final, wearable piece. There have been some great costumes created this way. Again, that’s not what I’m doing, but the prospect of having to explain and re-explain that isn’t terribly appealing.

Along a similar line, the 501st has been around for a long time. They’ve no doubt had countless people trying to apply and get approval with “unique ideas” or “unique approaches” or whatever else that are, objectively, pretty terrible. They’re tired of it, they’re cynical of anything that has even the vaguest aroma of this, and they’d rather steer such enthusiasm toward a non-terrible end product (and often end up dovetailing heavily with the “just buy a kit” crowd, as a result). I sympathize with this group; they have no reason to believe I’d be anything other than yet another in a very long parade of wannabes.

Finally, there are those who just seem to enjoy the entirety of the hobby and want to encourage participation and creativity as a whole. These seem, rather depressingly, to be the rarest sort. They do exist, though, so that’s something.

At the end of it all, I have to remember that I’m doing this for me. If it doesn’t pass someone else’s sniff test but it does pass mine (knowing just how high my bar is for myself), so be it. They just aren’t looking for the same thing I am.

Regardless, I have work to do.

Time And Relative Dimensions In Stormtroopers

 Posted by at 00:43  No Responses »
Aug 202015
 

This post is part of a meta-series. Click here for a list of all posts in this series.

You’d think after working on this project on-and-off for two years that any new setback would come as yet another dispiriting blow. For once, tonight’s setback is a huge win and even serves to make all of the previous setbacks — especially the CarveWright-related ones — seem like blessings in disguise.

You see, I had the size wrong all along.

I originally scaled the 3D helmet model in Blender to an approximation of my own head. I eyeballed it until the size looked right. Later, I found some actual measurements folks had taken of the molds from the films and checked those against my existing pieces, which seemed to line up correctly. Cool, my estimate had been correct out of the gates! Confident now that I was on the right path, I proceeded through all of the various updates you’ve read about this project. I occasionally spot-checked during the cardboard process to make sure I was still within expected tolerance of those dimensions. When I switched to the CarveWright, I was already set, since the Blender model hadn’t changed and the cardboard cross-sections had been correct in any event. Having now switched to paper, I continued on as before with the existing dimensions.

Before printing everything out on heavy-duty cardstock, I did a test print of just a few portions of the helmet in plain paper to get a feel for the method, check dimensions, sanity check my paper templates, and so on.

Plain paper 'dome' prototype

Lumpy, but promising. Size seemed pretty good when I put it over my head (dopey as I looked doing it…), so I started printing out the cardstock parts. Here’s the same set of templates, printed in cardstock, used to make the plain paper prototype.

The same templates, printed in cardstock, used to make the plain paper prototype

All in all, everything was coming together very nicely.

'Jowl' before... ...and after

More than any other time in the project, I felt like I was making real progress at last.

A face emerges

I got quite far along. Here’s where things stand as of right now.

Progress to date

All along, though, something’s been nagging me. Every time I held up the “face” to my face, every time I eyeballed the dome, it all felt really big. Having never actually handled a stormtrooper helmet of any variety in person before, I figured this was just expectations clashing with reality. But I’d hate to go through the entire process and screw up something as basic as the proper dimensions, so I started measuring things.

And they were too big. The helmet, which I expected to “stand” about 12″ tall, measured closer to 14″. Did I misprint? Scale something wrong in the process? I couldn’t have gotten the model wrong; I’d checked that against the research from that theRPF post…

…hadn’t I?

I jumped into Blender and threw down a 12″×12″×12″ cube…and it was smaller than my model!

What the hell? At what point had I overscaled it? Perhaps at no point. I may have deliberately underscaled the cardboard cutouts when I did them and forgotten about having done so somewhere along the way. Why I would’ve done that instead of scaling the Blender model, I couldn’t tell you. Maybe something to do with render resolution and creating consistently sized cross-sections? In any event, with the exception of those templates, my dimensions have been too big all along. Even if the CarveWright had worked perfectly, I’d’ve had a garbage mold that I’d need to re-carve.

But now…I actually have a testbed. It’s too big, sure, so I won’t be casting from it, but I’m so close to done with it that it’s actually a worthwhile guinea pig to test out other aspects of my approach: resin-and-fiberglass reinforcement, Bondo filling, sanding, and so on. It won’t need the same level of finish as the “real” one will, but it’ll give me free reign to learn and screw up without feeling tremendous loss.

What’s more, I can use everything I’ve learned about the Blender papercraft export plugin thus far along with the experience of having cut out all this stuff once before, to create better, more detailed, and easier-to-assemble templates than I did the first time through.

Catching this now is a huge win compared to catching it at any other point along the way and especially going forward. Color me relieved!

Pivot #3

 Posted by at 21:19  No Responses »
Aug 112015
 

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After struggling to get the CarveWright CNC carving machine to cooperate on-and-off over the last year or so, I’m ready to declare defeat on this approach. Every time I think I’ve got “the” problem solved, a new one crops up. First, I had the colorspace issues. Fixed that. Then, I had issues stemming from materials (MDF), so I swapped out for wood. Then I had issues with accuracy, that seemed to stem from the heightmap again. Wasn’t that. These accuracy issues continued to plague. I disassembled the machine, cleaned it, greased it, aligned it, calibrated it, and repeated the whole process numerous times. Once I thought I had it licked, I engaged in an ambitious many-hour carve to get all the pieces finally done…only to discover massive disparity between what I expected and what the final pieces measured, none of which seemed due to the data going in. I sought out advice on the CarveWright user forums, got some new ideas — perhaps I needed to calibrate the machine per board, for each carve in order to achieve the accuracy I sought, for example. But before I could test any of this, new issues appeared — now, boards wouldn’t even measure, complaining that there was a sensor roller error…when he board left the sensor roller because it had fed past it!

That was toward the end of April. The last straw came tonight, when I mustered up the courage to finally see about resolving these issues and test out this per-board calibration hypothesis. I couldn’t get the sensor roller to stop throwing errors, telling the machine to ignore the errors caused different errors to appear, and then — when taking apart the sandpaper belts that feed the board through the machine, I saw that the belts had started to “roll under” themselves again, which was an issue I fixed months ago. It was too much. There are parts I can look into replacing — newer, better; rubber belts instead of sandpaper, for instances — but that costs a great deal of money on top of the money already spent to acquire the machine in the first place (dramatically discounted though it was). I set out to prove that one could make a good-quality stormtrooper helmet on the cheap; this wasn’t that at all and I wasn’t about to keep throwing money at it.

Therefore, I’m changing my approach once again. While the cross-section approach is still something that I think has merit, I’ve come to the point now where I’ve seen enough successful projects that start from naught but paper that I’m going to give that a go. I’ve already got my 3D model, which needs only marginal tweaking to be suitable for that sort of approach, so I should lose little in the accuracy I hoped to achieve with the CarveWright, though I may not end up with a solid wood positive mold that I can pull numerous silicone negatives/poured urethane casts from. Maybe. Who knows, perhaps I will be able to create a mold this way and still use the silicone-and-urethane approach I planned to use all along.

Time to find out.