fraizer Posted October 31, 2018 Share Posted October 31, 2018 Background: Theo Jansen designs and builds creatures he calls Standbeests; they are quite large, wonderfully whimsical, and often wind-driven. Here’s a link to his website: www.strandbeest.com A few days ago, I decided to model a version of his Rhinoceros, not a particularly difficult task. Then - before building the model - I fell down the rabbit hole of trying to mimic the leg mechanism that drives the Beest the way it actually works. Not necessary to make a model animate, as a simple set of bones with basic key framing could do that job, but an interesting problem. I have been stuck in the rabbit hole for days. Rigging and constraints are not really my strong suit… The mechanism is deceptively simple; the leg is driven by a crankshaft offset from a pivot point about which the leg rotates. The motion of the leg is controlled from two directions with linkages fixing the range and direction of the motion. It took Jansen a while to determine the correct lengths for all the relationships, but once calculated, building a working model was straightforward. Here is a link to a simple wooden mock-up (GIF) with a hand-crank drive. Also on this page is a video of Jansen pulling his full-size Rhinoceros (as well as many other Beests): https://nerdist.com/walking-with-the-incredible-strandbeests-of-theo-jansen/ The reason I cannot get out of the rabbit hole is I have failed to find a bone structure / hierarchy and set of constraints that will drive the leg mechanism and not come apart. Not even close. I suspect I am missing something obvious. I did a forum search and found no references to Jansen or his Beests. I thought that strange as they are so interesting… Here is my simple leg model, without bones (except M, the crank); also the PNG rotoscope file (from Jansen’s site). The line segments are as close as they can be to Jansen’s holy numbers, in cm. Thoughts? Joseph Fraizer www.iconmine.com leg-mechanism-test08-deboned.mdl Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted October 31, 2018 Hash Fellow Share Posted October 31, 2018 That is an interesting challenge! I recall seeing videos of those contraptions on the beach a few years ago. Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 2, 2018 Author Share Posted November 2, 2018 With a little background help from Robcat, I have made an action that almost works. The mechanism moves as it should except for the C-bone which does not do its job. The action is 2 seconds, 30FPS; by using a key framing cheat at 0:15, 1:00, and 1:15 -- moving the C-bone and all other bones into correct positions -- I get very close to the characteristic gait of the Beest. Good enough for animation purposes. But I do not think this approach is the real solution to rigging the leg. Here is a new version of the model, boned. And the action I have developed. leg-mechanism-test09.mdl leg-motion-test09-working.act Quote Link to comment Share on other sites More sharing options...
serg2 Posted November 3, 2018 Share Posted November 3, 2018 Experiment 😀 MECH_05_RUNNER.prj 1 Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 3, 2018 Author Share Posted November 3, 2018 Very cool. It works much better than my attempt. I am still studying your bone, null, and constraint set-up. Cannot say I fully understand it just yet. Thank you. Quote Link to comment Share on other sites More sharing options...
serg2 Posted November 3, 2018 Share Posted November 3, 2018 I myself do not understand how this works. We need to work together to make a more universal installation for the study of the most optimal solution. Thank. Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 4, 2018 Hash Fellow Share Posted November 4, 2018 Hi Joseph, I did a walk thru of this at Live Answer time thinking I could just post the screencam of that for you, but my screencam system seemed not to work and still isn't working when i tried to do it again. I'll try to get back to you on this. Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 4, 2018 Hash Fellow Share Posted November 4, 2018 Hi Joseph, Here is a video walking through the set up. My solution is similar to Serge's The audio sync is bad, it will wander in and out of sync but i think you can follow it. clip4358BeestLeg1K.mp4 Quote Link to comment Share on other sites More sharing options...
serg2 Posted November 4, 2018 Share Posted November 4, 2018 How exactly the mechanism works for you, Holman! It is wonderful! 1 Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 4, 2018 Hash Fellow Share Posted November 4, 2018 Here is a zip with the PRJ with the leg both the undone (01) and done (06) form if you want to try it as in the video. BeastLegPRJ.zip 1 Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 4, 2018 Author Share Posted November 4, 2018 Robert, A brilliant solution and excellent explanation. For me, the key concept that I would never have arrived at is making bone F a child of bone B, without any intervening/connecting linkages. And your model and action are far simpler than my almost-works attempt. Simpler is always better in A:M world. Thank you. Joseph 1 Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 9, 2018 Author Share Posted November 9, 2018 Here is a movie of my Rhino-Beest model (so far). Looking at the video of Jansen's Rhinoceros, it appears that the six leg pairs (front + rear = pair) each have separate cycles. I decided to simplify the task of boning/constraining the model/action by making 3 pairs of bones/constraints and assigning CPs to leg bones so that the legs move symmetrically on either side of the model centerline. The action is driven by bones M1 through M6 which rotate around a common center and each move one of the leg mechanisms plus its respective CP doppelgänger. The walk cycle that seems to best resemble Jansen's Rhinoceros has pair M1-M2 (front-rear) set at 40 degrees apart, then an 80 degree gap followed by M3-M4, etc. Thanks again to Robert and Serge. Rhino-Beest-gait2.mov 1 Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 Looks like you'll need a different video format. That one doesn't play. Try MP4 Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 10, 2018 Author Share Posted November 10, 2018 It is MP4 in a MOV wrapper. Is this a Mac vs. Windows thing? The video plays for me...from the Hash website... Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 I suspect most people will not have MOV available anymore since Quicktime has been declared a security problem. It's off in my browser. Try just changing the extension to MP4. Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 10, 2018 Author Share Posted November 10, 2018 Extension changed. Seems to work?...? Rhino-Beest-gait2.mp4 Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 No, i don't see it yet. 😯 Does anyone else see it? What was the actual video compressor used? The MP4 I posted previously was h.264 Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 10, 2018 Author Share Posted November 10, 2018 TGA sequence was exported from Quicktime 7Pro compressed as MPEG-4 video. "Prepare for internet streaming" set to Fast Start. Default extension is MOV. I changed the extension to MP4. Does play for me. Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 Here's what happens for me. I'm not sure what is wrong... Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 10, 2018 Author Share Posted November 10, 2018 I am puzzled too. Usually these things "just work." I cannot effectively test other formats, etc., because everything works for me in my browser (Safari). Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 You could upload it to YouTube and put the Youtube link here. Quote Link to comment Share on other sites More sharing options...
fraizer Posted November 10, 2018 Author Share Posted November 10, 2018 YouTube it is. Here is the link: https://youtu.be/yLnrZywVnbA Sorry about the misfires... If anyone can provide a Mac-based workflow for reliably producing videos that will play in the forum -- much appreciated. 1 Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted November 10, 2018 Hash Fellow Share Posted November 10, 2018 Now I see it! It's a beest! Quote Link to comment Share on other sites More sharing options...
Guest Returning user Posted January 18, 2019 Share Posted January 18, 2019 Just got back into using Hash Animation Master. My version is 15 which came out in 2007. Obviously a lot has changed since then. The default animation format is mov and Quicktime is not on my Windows 10 Laptop and I've read that they stopped supporting it in January 2016 for security reasons. How exactly do you change the format from MOV? Quote Link to comment Share on other sites More sharing options...
fraizer Posted January 19, 2019 Author Share Posted January 19, 2019 Used to have a lot of Windows expertise, but no longer. The following is Mac-related. In A:M, I always render to a TGA sequence. If the program crashes mid-render, I can pick up where it crashed; no lost render (the .MOV) or render time. The format for render is selected in Camera settings, under Output Options. QT Pro7 is my workhorse for assembling the TGAs into a clip. QT Pro7 supports many output formats for clips. Usually I use the Animation codec as it preserves the Alpha channel (Colors = Millions+); also, by selecting Keyframe = All, the clip is essentially full quality, uncompressed. Other programs can perform these functions, but the work is really easy to do in QT Pro7. I do a lot of work in version 15, as well as version 17. From my perspective, v15 has aged quite well. Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted January 19, 2019 Hash Fellow Share Posted January 19, 2019 On 1/18/2019 at 3:35 AM, Guest Returning user said: Just got back into using Hash Animation Master. My version is 15 which came out in 2007. Obviously a lot has changed since then. The default animation format is mov and Quicktime is not on my Windows 10 Laptop and I've read that they stopped supporting it in January 2016 for security reasons. How exactly do you change the format from MOV? I put the reply in a new thread.. https://forums.hash.com/topic/48901-quicktime-gone-what-to-do/ Quote Link to comment Share on other sites More sharing options...
fraizer Posted January 19, 2019 Author Share Posted January 19, 2019 And provided some additional excellent detail. Thank you. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.