Temple Collapse Simulation

I hadn't touched Blender in months but I got back to it and figured out how to link objects with hinges. I took the original design and split off individual segments then connected them together how I wanted. The simulation isn't great since it's a rigid-body simulation so the parts act like they're infinitely hard rather than deforming and breaking under stress. I did set up most of the hinges to break under a high load as I would expect to happen in reality. Unfortunately the combination of rigid objects and breakable hinges means many of the pieces just pop off immediately.

In any case, the point is to demonstrate the way the Temple would collapse during the burn. Once the safety supports are removed for the burn, the first level would be held up by one or more thick hemp ropes wrapped around the main central posts. When the fire weakened the rope enough, it would break and unlace through the support, staying in the channel designed for this purpose. That would release all the sides at the same time and cause the whole Temple to collapse at once, giving it a definitive end.

The next step, I think, is to rework this backwards to show how I intend the first level to be assembled—basically in reverse of collapse. I think if I do that, I can get Blender to fit the pieces together without being under exploding pressure.

Continue reading "Temple Collapse Simulation"

189 total views, 1 views today

Some Rough Dimensions

I do need to go back to this last 3D model in Blender once more—if only to measure some dimensions. For visual clarity, I should add them to the images, but I don't feel like learning how to do that, and I really just want to get a rough idea anyway.

On the ground, the base of the trunk is 17' (5m) across. The area inside the trunk is a circular area about 13' (4m) across and 12' (3.5m) to 13' (4m) tall. This will probably get a bit shorter since the roof seems a bit thin, and that's what carries the bulk of the weight.

The first level is about 62' (19m) across, meaning it extends over the ground about 22.5' (7m) out from the trunk. Standing on the first level, the trunk is much narrower at 8.5' (2.5m) across. The second level is about 46.5' (14m) across, and the top branches are about 40.5' (12.5m) across.

The bottom of the first level is about 12' (3.5m) to 16.5' (5m) high, and its walking surface runs from about 13.5' (4m) to 18' (5.5m) off the ground. On the first level, there is about 7' (2m) to 7.5' (2.5m) of headroom to the second level whose walking surface is about 23' (7m) to 28.5' (8.5m) off the ground.

The branches at the top are only about 5' (1.5m) to 6' (2m) above the second level, so I might need to raise them. As it stands now, the top branches are about 31' (9.5m) off the ground with the very tips reaching as high as 35' (11m).

The tl;dr is that the trunk is 17' (5m) across, the whole Temple of Seasons is about 62' (19m) across and about 35' (11m) tall.

For comparison, the last Temple I experienced was the Temple of Whollyness in 2013 which claimed a central pyramid with a base that's 88'x88' (27m x 27m) and 64' (20m) tall with additional work that extends the base to 116'x116' (36m x 36m)—for all intents and purposes about twice as tall and twice as big across. This is similar in scale to 2014's Temple of Grace which was "70+' high, and had a footprint of 80'x80'; it sat in a courtyard approximately 150'x150'" In fact, it seems like this is the approximate size of most of the temples, and the scale is only growing.

212 total views, no views today

Rendered Leaves

I got back to Blender and added a couple passes of leaves. I simply floated them below each of the twigs, expecting up to 4 on each one. On the "sparse" view, I put one leaf on about half the twigs.

3D-render from nearby with a sparse set of 232 leaves.

It's kind of hard to see the sparse collection, so here's the "man on the branch" view:

Person standing on the lower level with guard rails, small branches, twigs visible, and a sparse set of 232 leaves.

And then I went ahead and filled out nearly all the open slots—I think there's about 200 empty with 2,008 filled. Again from the branch-view for comparison-sake:

Person standing on the lower level with guard rails, small branches, twigs visible, and a dense set of 2,008 leaves.

Finally, I've been enamored of the "far-away" view even though I haven't posted much:

3D-render far-away view with 2,008 leaves added.

I think this pretty much concludes my work with this particular 3D model. Right now I can see making two models in the future: first is one that will be the basic shell with the mechanics to allow it to be assembled, and how it will collapse; second is a final design that will be a board-by-board construction that should really drive me insane. One change would be to go with 2×3 lumber for the twigs instead of 2x4s. This would make the twigs look, well, more twiggy and allow the leaves to stand out more.

In thinking about the next stage, I'm thinking that the crowning branches might not be worth having—at least not in the thick form they are now. From my first idea of how the Temple would be, I kind of knew how the lower level would be assembled and how it would collapse. Recently I devised a way for the second tier to be added, modelling it after a kind of scissor-jack that would raise it into place. That would also allow it to collapse straight down as the lower-level split outward.

246 total views, 2 views today

The Mechanical Elevator

Initially I considered a ramp that complied with Americans with Disabilities Act of 1990 (ADA) § 4.8: with railings, a slope of no more than 1:12, and flat landings for each 30 inches (760 mm) of rise. With these requirements, this ramp would need to be nearly 160 feet (48 meters) long including five 5' (1.5m) landings just to reach the first level. To achieve this in a single 360° sweep, it would need to be about 25' (8m) from the center of the Temple, placing it at the outermost reach of the branches.

So as an alternative, I thought of a mechanical elevator to permit participants to lift and lower others. Instead of using winches or electric motors, the idea is for it to operate entirely on counterweights. The permanent counterweights would be installed so the car comes to rest at the first level of the Temple (top). That way someone could use it without assistance in the case of an emergency. To raise the lift, participants would act as human counterweights on a smaller side-car to hoist the main car to the first level.

To avoid the cars moving too quickly, a mechanical governor would limit the speed of travel both ways. By keeping the system largely mechanical, I figure I can avoid failures of higher-tech solutions.

In the end, I know this is not ideal as it doesn't offer complete access: the lift would permit any participant to reach the first level but not the second.

232 total views, no views today

Considering the Burn

From the beginning, I have been adamant that the Temple burn in such a way that it will conclude with the tree-like structure splitting open in four quadrants. In thinking about the most recent designs, I couldn't figure out how to handle the three distinct levels. If the entire tree splits, the topmost branches—at some 30' (9m) tall would have a tremendous amount of momentum that would tend to fling burning lumber into the crowd. For the first level, this is not an issue as it is only about 10' (3m) high so the momentum outward would be substantially smaller.

For now, I am considering the idea of the first level falling outward while the upper levels fall straight down. To avoid a tall portion of the Temple landing upright in the ground, the supports from the first to second level would fold outward: they would tie the center of the second level to an anchor on each section of the four splitting parts of the first level. The second level itself (likewise the third level) would be a solid structure that would not be designed to fall outward like the first level. Thus, the support for the second level would split outward with the quadrants of the first level while the second and third levels would tend to fall straight downward. Although the support from the second to the third level would be solid, being weakened by the fire and the direct 20' (6m) drop will at least weaken it severely, if not demolish it instantly.

184 total views, no views today

Filling out the Lower Level

I got back to Blender today and quickly added some twigs to the lower-level branches. I was almost done and it crashed so I had to do it again … faster the second time, so there's good and bad with that. My eyes were going a bit crazy trying to see where to place things as it got quite dense. I think it's too cluttered with branches to permit leaves to hang off the twigs (at least without getting all tangled with one another) but I'll have to wait and put fresh eyes on it another day.

3D-render with guard rail posts, small branches and twigs on the lower level.

It's getting kind of hard to see, so I have another angle I've been playing with that's a person standing on the lower level:

Person standing on the lower level with guard rails, small branches, and twigs visible.

I'm not thrilled with this result, and having only added 50 twigs, it's not enough to get close to my earlier estimates of the number of leaves for solid coverage. I figure I'll have about 4 spots for leaves on each twig or branch. In these images, there are 268 lower small branches, 50 twigs, and 124 upper small branches for total of 442. With 4 on each one, that's only 1,768 close to the sparse fill with 1,900—although that was an even distribution on a hemisphere and not in a pattern mostly on the outer sides. By not filling in the top, it makes for an odd kind of tree, but one that seems to look okay looking from the ground.

207 total views, no views today

Hang the Branches from Above

Starting with the idea I had with making canopies—by hanging thinner branches from above rather than supporting from below—I came up with a way to make a 3D test of that idea. I started by making guard-rail posts around the perimeter of the elevated trunks that people walk on. Working upward, many of the posts would have a rope to anchor the bottom of a branch. On the lower elevated level, the tips of the branches would have a rope tied to another branch which would have holes to hang leaves with messages; the upper level would only have the main branches to hang leaves. The tips of all these branches would be anchored from above with ropes to the next level up.

This way, the branches will sway with the wind with a great deal of flexibility. Further, for any that break, the rope or rigid branch can both be replaced on the Playa. If the branches had been rigidly attached from below, flexing of the branches would be difficult to achieve, and they would be prone to permanent breakage.

For now, I only rendered the first set of branches, omitting the forks on the lower elevated level. I also omitted any anchors, simply placing the branches how I would like them to appear.

3D-render with small branches and guard rail posts.

210 total views, no views today

A Simple 3D Canopy Demonstration

I decided to try splitting the second-story branches for better coverage. The idea is to use ropes from the first level branches on upward, tangled to tension, to emulate the finer branches that would hold the leaves.

3D-render with second-tier branches split.

Just to get an idea of what the canopy might look like, I fiddled around with making 4"x6" (100mm x 150mm) rectangular "leaves"—about the size I could expect from using the slats from palettes. I just applied them in a hemispherical dome. I started with a modest number that could be easily realized—some 1,900 leaves.

3D render with a uniform half-dome of 1,900 rectangular "leaves."

I thought I'd go a little crazy and see how dense the shadow would get if I pushed it to 11,000 leaves. I would guess this would be a very optimistic goal to achieve, but not complete out of reach.

3D render with a uniform half-dome of 11,000 rectangular "leaves."

223 total views, no views today

Idea for Safety Lighting for Cables

Looking at a blinking yellow warning light, I got to thinking about how to mark any heavy cabling to secure the Temple during the event. In day, there is less concern as simply adding some ribbon would work. At night I thought to have a LED projection along the length of the cable. Then I figured side-emitting fiber-optic cords would be nice, lit green for optimal visibility. This led me to spiral the fiber-optics, and it would kind of look like a vine climbing, perhaps like an electronic morning glory.

On the technical side, I figured 1 watt of LED light would be plenty, but I'd like to have a redundant pair on each cable. This would mean about 10 watt-hours each per night which could be recharged by a 2W solar cell. But for the sake of using 10 watt-hours for, say, 8 nights, that's just 80 watt-hours. Quality alkaline D-cell batteries are typically 10 amp-hours at 1.5V or about 15 watt-hours each, so it would take a minimum of 6 batteries to hit that mark. A simple resistor circuit could drop a series-parallel pack wired for 4.5 volts to the necessary 3.5 volts at 280mA[1. Estimated from Luxeon Star-III specification sheet, rated for 700mA @ 3.5V = 2.5W]. The current would draw symmetrically (theoretically) from each chain of 4.5V, so the runtime on the battery would be a total of 10AH / 0.14A = 71 hours. (The discrepancy from 90 hours is because it's 280mA at 4.5V which is more like 1.3W. What will happen, though, is the light will get slightly dimmer and the battery last longer. The resistor is fixed at 1V / 280mA = 3.6Ω, so when the battery has dropped to 4V, the resistor drop is only 0.5V, and so the current is 0.5V / 3.6Ω = 140mA.)

I guess that got way too technical too fast. Oh well.

233 total views, no views today

Canopies

I was just out walking around the neighborhood and I realized that trees tend to place their leaves on the outer periphery of the branches. It forms a canopy—which, I guess is why we use the same word for a forest's treetops and a kind of roof.

I think this is what is making my tree models look so weird and sparse. I think I can string ropes to form a kind of quasi-organic geodesic dome that would provide the hooks upon which to attach the leaves. That was another sticking point in the design: how to create nodes where one could hang jeir message. I was pondering making some kind of wooden branches, but they'd be likely to snap in high winds.

241 total views, no views today