Bongo 3.0 WIP 6

Hi @altamiro.aj ,
regarding doing this with Kangaroo-

That sounds like something wrong in your setup - for something simple like this it should be effectively instantaneous.


One thing to watch out for that might be why you were experience slow results - if you have a complex dense mesh, do not input all the vertices as points to the rigid body - only the ones needed for your constraints and interaction.

For instance - here’s a linkage where each part is a ~5MB mesh

1 Like

No, and I understand that is frustrating. I’ve logged the issue here since I couldn’t find an existing one. The views themselves can be animated though. Here’s a quick example.

Yes, Bongo handles these as animation sets. You can read a bit more about them in the Animation Sets tutorial.

@Luc 's models can be downloaded from the Google Drive folder here.

1 Like

This is a setup of the Pitch Control model used to observe the operation of the mechanism, rather than portray it in a video.

The steering disc is given only one keyframe at tick 0. The entries in this keyframe are used like a parameter to investigate the effect on the blades. The timeline can be used to follow the result of the rotation.

The 3 ‘observation’ views are animated in such way that the camera follows the rotation of the system.

1 Like

Your longing for sliders to control the mechanism got me thinking. Currently the Expressions section of keyframes can be used not only to enter expressions but also as a kind of a ‘constant’ simply by entering a value. So let’s see if we can add a slider interface to adjust the value and there we are… a parameter. https://mcneel.myjetbrains.com/youtrack/issue/BO-3297

1 Like

This way of setting up the observers and being able to see then in real time at same moment is a really clever way of doing something in a easier way than what I do now.

Thank you, I hope it works out :slightly_smiling_face:

1 Like

Bongo 3 displays red constraint icons in the model. Some of these icons are shown in the following screenshot. I believe that these icons should be clickable so that we can EASILY change the constraints.

1 Like

That’s a good idea. We have the bug logged here. I’ll try to find some time for it.

https://mcneel.myjetbrains.com/youtrack/issue/BO-3210

Hellow,I want to know how to make a Cam animation

23

1 Like

Hi,

Excellent structures to explore the marvels of Physics. Stuff for a tutorial video. Meanwhile some explanations. For starters : all the following models were made in WIP 7 (not 6) Bongo 3.0 WIP 7 - #4 by Luc

Model B 1138590816 B.3dm (609.7 KB)

Model B is really quite simple.
Both the rotor and the square ring are Physics enabled. The white sleeves are merely decorative, simply to make the image complete.
The rotor is connected to the World by a Spindle. This spindle is given angular velocity (a novelty since WIP 7 – the unit is radians/second). You can use the BongoConnectionsManager command to see the Connections.


The square ring is connected to the World by a Slider, and that’s it.
For both Physical objects the Object Parameters ‘Restitution‘ and ‘Friction’ are set to minimum.

The margin setting (an absolute requirement in Physics)is still in a highly experimental phase in WIP 7. The objects of the models used this post are built observing a interspace of at least 0.04 units (cm in this case). The default Physics Shape setting (Margin 0.04 + Offset enabled) in combination with my favorite setting in the Time manager of ‘Steps per second’= 300 and ‘Solver Iterations’=150, functions satisfactorily for this model.

Model A 1138590816 A.3dm (648.1 KB)

In Model A the rotor is rotated by Keyframes (just like in Bongo 2). This is a equivalent alternative to the use of ‘motor’ connections. The object is Physics enabled and marked “Kinematic” – what is necessary for it to meet its keyframe parameters.

The wheel is Spindle-connected to the shackle, which in its turn is Slider-connected to the World. The wheel is Gravity enabled. Both rotor and wheel are set; Restitution = minimum, Friction = maximum. The Physics Mash Quality is set to medium in order to have a smooth contact between the curvatures. Because the objects are built with consideration of (at least) 0.04 units (cm) interspace the ‘Offset shape’ can be disabled, hence avoiding intersection of the objects during motion. A smaller margin setting (0.02 units (cm)) even brings both wheels closer together.
Don’t try ZERO margin – Rhino crashes.

You may notice model A kind of ‘freezes’ during Precalculation. Don’t worry; Rhino will regain consciousness after a short while (about 30 seconds on my laptop). Apparently this is an enigma for the developers.

I have always found that the lack of surface-to-surface constraint was a shortcoming in Bongo’s 2.0 Inverse Kinematic, just like the elasticity of a spring. Physics offers both features and more. The price to pay is the multiplicity of parameters which play a role in Physics. Hopefully in the further we can bring some harmony and coherence in this as well as the highly necessary documentation.

A cute variation. 1138590816 C.3dm (595.1 KB)

Luc

6 Likes

Hi, Luc, first of all, thank you very much for your detailed reply which solves my thinking day and night confusion. :rofl: :smiling_face_with_three_hearts:Well, as you said, the building of future Bongo will add more Physics function, we all hope Bongo can test most mechanical movement like Ug or SolidWorks. That will be a very meaningful work.

1 Like

Tiny Correction. It’s not per se a zero margin that causing a crash. It’s zero margin combined with “Offset shape by margin” enabled. Will be fixed in the WIP 8.