I have a part that has to rotate about two axes with different pivot points. Does anyone know how a secondary axis can be added? Or How to add an additional pivot point can be included into the moving part?
Mostly an auxiliary object (usually a point) being child or parent does the trick.
Could you please be more specific in how the object is supposed to rotate about 2 axis. Is the rotation simultaneously or in succession? Is the ’part’ connected to others?
Maybe you can show an image, a drawing or a model.
Thank you for getting back to me.
There are two sub-set of parts that are moving together. The sub-set B which has some moving parts in them, is connected to sub-set A, . The sub-set A moving/rotating upward taking sub-set B with them. Once the rotation of sub-set A get to some angle ( ie 75 deg) a part in Sub-set B has to rotation 90 deg.
I have tried a few different way, but did not get results.
I didn’t have to look for an auxiliary object. The rods in you model in fact play that role.
In Shahin 000.3dm (77.0 KB) the green cube is made child of the blue rod. Both are made rotating by means of keyframes. Hierarchy does the rest.
The other 3 rods can be rotated on it’s one.
I hope this is what you are looking for?
Thank you for taking time to build a model. I really appreciate your effort; wow. That is very nice of you.
You are correct, the green cub is child to the bar. However, I have added two components to the model; a Magenta box and a Yellow rod.
The magenta box needs to rotate 90 degree about the Yellow rod axis, when the arms move the green box to the top. I have problem with that!!
Shahin 000.3dm (104 KB)
No prob. Support is my mission, and a model says more than a thousand words (old chinese proverb).
Shahin 001.3dm (115.2 KB)
- Make the magenta box child of the green one.
- Move the pivot to the centre of the yellow rod.
- Make the magenta box rotate X by keyframes
If you want the yellow rod to take part; just make it child of the green box.
Or apply the steps above to the yellow rod and make the magenta box child of the yellow rod.
BTW Welcome to our community.
I go the magenta box the do the correct action.
Thank you very much for your help.
Shahin 000.3dm (85.8 KB)
Good Afternoon Luc,
I have two problem with my Rhino I cannot solve.
In the attached file, I am trying to setup a sample for a landing gear struts. I have no idea how to make the one of the ram to stay attached the main arm that holds the main arm. They rotate, but I need them to stay together and attached to each other in pivot points. How do I connect them?
The other issue I have is that I cannot get the Bongo tool bar to show us in other tool tables.
I appreciate if you can help me with these items.
Again, I am really sorry to bug you!
Landing Gear.3dm (119 KB)
Whenever you seem to need a second pivot on an object you must think “auxiliary object”!
I tried to make this clear in the tutorial video http://bongo.rhino3d.com/video/the-conception-of-an-ik-chain-a-scissor-arm. I also hope you have seem http://bongo.rhino3d.com/video/whys-of-ik which explains the basics of IK.
In your model you made objects 0 and 33 rotate through keyframes and at the same time a IK ‘Hinge’. This is not common practice. An object is either ‘forced’ to rotate by keyframe data, or it is allowed to rotate freely to accommodate one or more constraints in a IK structure. In your model the Hinge do not function as such because there is no ‘constraint’.
The landing gear is perfectly suited for the use of IK.
In Landing Gear 001.3dm (129.0 KB) I arranged the first step of the motion. In the IK panel of the Animation manager it’s clear to see this is a simple ‘hinging’ chain ‘driven’ at the top by the keyframes of Object 33 and constrained at the end by an auxiliary object (for which the circle Object 49 was effortlessly at hand).
In Landing Gear 002.3dm (115.8 KB) the second part is attached to the first.
To begin with I turned the group representing the wheel into a Block. This is necessary because a group cannot have children, which in this case is needed for the IK-chain. The wheel is attached by a Hinge to the first part of the gear, and the hinging connecting rod is again constrained at the end by an auxiliary object (again the circle).
I hope you get the drift. If not, don’t hesitate to ask. It’s no bother at all, I enjoy tutoring.
Thank you very much, The tutorial video along with your explanation is very nice. I really appreciate you helping me work through these items. I’m going to watch these videos.
Also, another issue that I have is that Bongo’s tool tab does not show in my tool bar! I followed some in instruction on web to make tab appear again, but I am very sure I am missing an step.
Right click somewhere in the area with the toolbar-tabs (the cursor turns into ‘move’).A menu appears
Click “Show toolbar”.
In the toolbar-list that appears go all the way down.
There you can check the 4 Bongo toolbars.
Thank you for the help. But I don’t get the Bongo item under the Bongo 20.V50. I have just Toobar group that happen to be empty.
@marika_almgren : can you lend a hand?
If you in Rhino go to: Tools > Toolbar Layout, do you see any mention of a Bongo20v50?
If not than go to (in the same dialog) File > Open. Navigate to C:\Users"Your user name here"\AppData\Roaming\McNeel\Bongo\2.0\
In that folder you should have the Bongo20v50 and Bongo20v60, pick the one that fits your Rhino version and press Open. Now you should have the Bongo toolbar.
Thank you so much for the help.
I have Bongo 20.V50. There is a Toolbar group in there, but when it is checked marked, an empty toolbar shows up with smiley face on it.
Thank you luc, I appreciate your help.
Just go to C:\Program Files\Bongo 2.0 (64-bit)\Support in there you should have the original rui file. Just copy that one into the C:\Users"Your user name here"\AppData\Roaming\McNeel\Bongo\2.0\ folder and replace the faulty “smiley” one.
Thank you very much. It worked.
However, how do delete the two empty tabs on my tool bar?
The easiest way to get rid of them is probably to just drag them off so that they aren’t docked and then when they’re floating, press the x in the upper right corner.