H-015 measurements

[Markus]

Here are some measurements of the H-015 droid, based on the images from “Star Wars: The Force Awakens Visual Dictionary” and “The art of Star Wars: The Force Awakens”. I am using the comparison with the person to determine the height.
   
The droid is one third of the person. Assuming the person to be 70", this gives a height of 23 1/4" (without the antennas). The absolute height is then used to scale the relative vertical measurements from the next image, in order to obtain the vertical sizes.
   
In the next image, the droid is shown approximately from an angle of 45 degrees. The horizontal measurements of the diagonal widths are divided by sqrt(2) to convert them into the lengths of the sides. The ratio of these lengths and the height (in this image) is then multiplied with the known height which provides the absolute widths, as indicated in the image.
   
The height and the width at the bottom (27 9/16") are in agreement with the values that are mentioned by savagecreature in his Build log.

[kresty]

I added a PDF of Savage's skirt main and corner bits annotated with mm dimensions 'cause I needed measurements.
http://rebeldroids.net/gallery/displayim...play_media

I noticed that the corner angles are "close" to pretty common values like 45 degrees and 60 degrees. Makes me wonder if the original blueprints were cut to those values?

I expect my measurements are slightly off as these are of Savage's flatpack plans, and I expect he's adjusting for the styrene thickness. That error is irrelevant for my purposes.

[kresty]

I want to start by saying that Savage's plans are brilliant, I'm not suggesting they be changed.  I started looking into this because I couldn't figure out how to get the Lego to fit under the skirt. My figures are as much as 7% larger than the skirt in the plans.

I wish I had better pictures....  Anyhoo, Oliver built a ruler into the droid when he put Lego greebles on the bottom.  Lego studs are 8mm across.  The short flat tiles are 3.2mm tall, and bricks are 3 tiles (plates) tall, or 9.6mm.  (Trivia: they aren't square, so to make a cube you have to have 5 plates (or 1 2/3 bricks) 2 studs wide for a 16mm cube).

When investigating the Lego greebles it seems like they are perhaps 64 studs wide. That is 512 mm, and that won't fit in the skirt, which has an opening of about 506mm - That's 6mm too small even completely ignoring that the Lego is recessed from the edge a bit and raised up under the skirt as well.

Anyway, since my Lego didn't seem to fit in the plans, I started looking at the ruler.  The catch is that the camera has parallax and lens distortions that make using that ruler hard - however there are some clues I could figure out from a few of the photos.

First is that each edge has a "center" (for Alan & Giles that's the same as centre ;-)  Oliver cut the omniwheel ports manually, and they aren't the same, but the variance is small, maybe 1/2 a Lego stud.  Even so, we can find the center on this image:

Center of Sentry Droid bottom greebles
Finding the center of a side of bottom Lego greebles

The row indicated by the cyan horizontal marks are at the same "depth", the Lego from one end would run straight to the other end, though Oliver put a few details in front of that row.

We can see the ends of that row near the omniwheels are 32 studs apart from each other.  So the center is 16 studs from either edge at the turquoise mark.

The center is important because the "straight" photos of the edge exhibit parallax and lens curvature problems.  So we can't just look at the straight photo and see how many bricks we can see.

Instead we have to look near the edges to find a photo where the parallax is small and we're looking as close as possible to straight on at the edge of a brick.  The right side was a total loss as far as I can tell, however I have a couple images on the left side that are pretty close.  And since we know the center, we can just double that distance.

I found two images on the left side where we can see the same brick, however the parallax error is going in different directions.

Sentry Droid Lego ruler edge parallax
We can't tell exactly where the Lego aligns from these two images, but we can tell where it must lie between.

On the left image we can see that the bricks about where the blue line are have an edge perpendicular to the camera lens. Maybe not exactly there, but close. On the pink line we can see the right edge of that brick. The edge of our skirt seems to be about where the light green line is, however since we can see a little bit of the right edge of the nearby brick, we know that line is probably a little far to the left of the actual alignment point.

In the right image we have the opposite. We can see the left side of the brick we previously saw the right side of, and below the green line where our edge would lie based on the left image, we can see the left side of another brick. So we can tell that the purple line in this image is going to be too far to the right of the actual edge we're trying to measure.

You can also see that the same thing happens in the vertical direction as the camera was significantly lower in the right picture. That doesn't impact our measurement, but we can see more of the top of the bricks so it looks a little different.

Sticking that on our Lego model, we can see that those marks are 24.5 to 25 studs. Double that for the full edge and the bottom edge of the skirt must be near 49 or 50 studs long.

Sentry Droid Lego ruler
Measuring distance long bottom edge of skirt

Each Lego stud is 8mm, so using the Lego ruler tells us that the bottom edge of the skirt must be 392-400mm long. Current plans are 373mm for that dimension.

[kresty]

I started this by saying that the Lego greebles I'm mapping out don't seem to fit. I'm not completely certain (yet) about the total width as I don't have the corners completely solved, however increasing the area under the skirt by 5% would probably allow enough room for the Lego greebles to fit. Alternatively, we could cut the greebles shorter.

[Markus]

I started this by saying that the Lego greebles I'm mapping out don't seem to fit.  I'm not completely certain (yet) about the total width as I don't have the corners completely solved, however increasing the area under the skirt by 5% would probably allow enough room for the Lego greebles to fit.  Alternatively, we could cut the greebles shorter.

My earlier measurements, which agreed very well with savagecreature's, were based on this image plus the assumption that the person measures 70". If we increase this by 5%, this would become 74" or 6'2". This is still very reasonable. We could even increase this by 10% which would make the person 6'5" - which is still smaller than Darth Vader's 6'8".

There is now a new reference: the video from the Star Wars Celebration. At 3:34 or 3:44 you can see H015 moving past a sitting person, and it's just as tall as the height of the person's legs. If I adjust my office chair to have a similar sitting position, I measure a height of 25 1/2" which is approximately 10% higher than the earlier result.

For my H015 it does not matter, since it's anyway below the original size. I just would have to state that it's 64% instead of 70%...

[kresty]

If I adjust my office chair to have a similar sitting position, I measure a height of 25 1/2" which is approximately 10% higher than the earlier result.

My estimate shows 5-7%, I suspect it isn't more than that. I believe the Lego makes a "pretty good" ruler compared to the other things we have. I didn't upload all of my photos to the gallery, but I think most of the reasonably useful ones are there. I thought I'd posted this one, but guess I missed it:

Oliver and Sentry Droid

Now we just need to ask Oliver how tall he is ;-) (Maybe 39% of an Oliver, and Oliver's not on the tall side? It also looks like he might be behind the droid, and its hard to figure where the droid is near his foot, even if that is the same plane). This discussion hurts my head.

[Markus]

Here is the image that I had in mind.
   

[kresty]

Here is the image that I had in mind.

If I'd only thought to take a tape measure to the chairs!  The droid's in front of the chair though, so it's still tough, I suspect other photos provide more accuracy.

I'm wondering if the skirt is more splayed than expected as the head seems pretty accurate as far as I can tell from my photos?

[savagecreature]

We do actually have some things that are better than lego, at least for establishing some things. For some parts of the droid I have actual measurements.  
I arrived at the measurements I used something like this:  I would look to see a measurement I actually had real data on then I would go through the available photographs looking to see where that measurement was visible and as close to perpendicular to the angle of view of the camera as possible. Then I would bring the images into a 3D environment as a plane and use the good data to establish a scale. When I had the scale I would then measure all the other lines of the droid that were parallel to the one I had good data on.
I did that across multiple images, documenting all of the results for the lines I didn't have hard data on, then I took those values and averaged them, removing extreme outliers.  
Once I had those dimensions I put them back into a 3D environment and created geometry based on those dimensions, always propagating the hard data (the stuff I actually had measurements for).  When the geometry was assembled I projected the photos on to the geometry to establish if the proportions were within acceptable tolerances. If they weren't, I started over for that piece of geometry.

I can say that the line indicated in the image is, without a doubt, 13.13 inches on at least one of the Sentry droids. (I have images and data on more than one of them and they were noticeably different in some ways from one to the next)

The plans I released were an amalgam of all the data I had from multiple droids.

None of that is meant to imply I didn't make any errors. I'm quite sure I did. kresty had just asked about my methods so I figured I'd document them. Also, maybe knowing that measurement will help. I based a lot of stuff on that particular one as that edge is visible is so many images and being horizontal is more often less affected by foreshortening.

[kresty]

To be clear (again), I'm not questioning Savage's methods, those plans are brilliant and far more accurate that I could've done.

Totally agree that the 13.13" measurement is accurate +/- 0.7% tolerance And I don't see any obvious errors, in the rest of it. The overall size also seems pretty accurate, from the chair & Oliver photos. My problem is that I'm just trying to reconcile the Lego "not fitting". I'd be less worried if it was just me, but other folks are interested in the Lego greebles, so I'm trying to faithful in their reproduction. I'd love someone to point out errors in my logic.

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As an aside, I noticed that the angles on the bottom panels are really close to 45 & 60 degrees. Makes me wonder if Oliver started with 45 & 60? (though the flat pack is close enough that doesn't make any difference, just makes me wonder).