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Cannot add key points in Motion Analysis?

Question asked by Ben Cowden on Oct 15, 2012
Latest reply on Oct 28, 2012 by Jim Boland

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Hello all,

I am modelling a series of pendula, which I want to animate.

I am using Motion Analysis to get the most realistic application of gravity on the pendula.

What I want is for each pendulum to begin its motion at a different time during the animation (first one right away, then the second one a few seconds later, etc.)

But what I am finding is that I cannot add key points and "tween" animations in Motion Analysis.

When I add them, I get a mouse-over message that says they don't work except in "Assembly Motion studies" (see attached image)

Dragging components and adding Key Points works fine in Animation mode, but gravity is not available.

Is it really impossible to use gravity and key points in one animation?

Any advice on how to make a component move and then be effected by gravity partway through?

I am baffled. Any help would be warmly received.

I am using Solidworks 2009.

Thanks,

Ben

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Deepak Gupta Oct 16, 2012 2:29 AM

Welcome to SolidWorks forums Ben.

Did you tried switching to Basic motion option instead of motion analysis (click on the arrow next to motion analysis and pick basic motion from the drop down).

Also what kind of key you're trying to place. Can you upload your files here to check.

Please use "advanced editor" in case you want to attach any files.

You might also find this post helpful for your future reference.

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Ben Cowden @ Deepak Gupta on Oct 16, 2012 11:58 AM

Thanks Deepak,

Unfortunately, Basic Motion mode does not apply gravity realistically for a pendulum (falling objects do not accelerate, they simply drop at terminal velocity). So it needs to be Motion Analysis mode. Either way, I could not get Key Points to work in Basic Motion either.

I am using the Key Point button (the diamond with the +):

Are there other types of Keys?

I cannot find any documentation that indicates Key Points are not available in Motion Analysis mode, and it seems bizarre to disable it.

I have attached the file as it is here (please note it is very rough yet--I wanted to make sure I could animate it correctly before fleshing out the model, and that is where I am stuck).

Thanks,

Ben

Attachments

ConcentricPendula.TestAssem.SLDASM.zip1.6 MB

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Deepak Gupta @ Ben Cowden on Oct 16, 2012 1:55 PM

Ben you need to include all the parts files too to check the issue. To include all of them, open your assembly and pick Pack and Go from the file menu. There you would find the option to zip all the files. Once you make that zip file, upload that here to check.

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Ben Cowden @ Deepak Gupta on Oct 16, 2012 3:41 PM

Hi Deepak,

Here is the zipped Pack and Go file.

Thanks,

Ben

Attachments

BCowden.CPendula.zip2.5 MB

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Deepak Gupta @ Ben Cowden on Oct 17, 2012 11:01 PM

Ben, I'm not sure as what is the reason as I'm able to add them. The only difference is that I'm using SW2012/SW2013 and unfortunately I don't have SW2009 to exactly figure out the issue. So if you send these file to you VAR or someone one the forums who has SW2009 Premium might be able to help you. Sorry for the not being able to help out.

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Jim Boland Oct 28, 2012 5:35 PM

The problem here is your basic understanding of how animations are calculated. In an Animation motion study, all motion is based on descrete postions at descrete times, in other words Key Points. There is no physics involved and the component motion is determined by the distance and time between points and the frame rate. Parts can move through each other and they can move with infinite velocity and acceleration.

In Basic Motion and Motion Analysis type studies, the components must follow the laws of physics. The only key points for components are the key points a time zero as these are the intitial position for each component. Once the calculation starts, the solver moves ahead a very small time step and calculates the postion of all components based on the motion drivers (forces, torques, gravity, motors, etc) and the joints (mates). This continues until the end of the study. You cannot add key points for components as that would not make sense in a physics based solution.

If I understand what you want to do, you can take your intital motion study and duplicate it. In each study, move the timebar to zero and then move the individual pendulums to the starting positions you want and calculate the sutdy. This way, you can have many variations of the pendulum motion.

Also note that the fact that you cannot add key points to components in physics based studies is documented in the only book devoted to creating animations "Creating Animations Using SolidWorks" available from the SolidWorks merchandise store at http://store.solidworks.com.

Also note, that while it does not apply to your problem, physics based results can be used in animation motion studies by importing the results of the physics based solution into an animation motion study using the Animation Wizard.

Hope that helps.

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6 Replies

Deepak Gupta Oct 16, 2012 2:29 AM
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Welcome to SolidWorks forums Ben.

Did you tried switching to Basic motion option instead of motion analysis (click on the arrow next to motion analysis and pick basic motion from the drop down).

Also what kind of key you're trying to place. Can you upload your files here to check.

Please use "advanced editor" in case you want to attach any files.

You might also find this post helpful for your future reference.
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- Ben Cowden @ Deepak Gupta on Oct 16, 2012 11:58 AM
  Mark Correct
  Correct Answer
  Thanks Deepak,
  
  Unfortunately, Basic Motion mode does not apply gravity realistically for a pendulum (falling objects do not accelerate, they simply drop at terminal velocity). So it needs to be Motion Analysis mode. Either way, I could not get Key Points to work in Basic Motion either.
  
  I am using the Key Point button (the diamond with the +):
  Are there other types of Keys?
  
  I cannot find any documentation that indicates Key Points are not available in Motion Analysis mode, and it seems bizarre to disable it.
  
  I have attached the file as it is here (please note it is very rough yet--I wanted to make sure I could animate it correctly before fleshing out the model, and that is where I am stuck).
  
  Thanks,
  Ben
  Attachments
  - ConcentricPendula.TestAssem.SLDASM.zip1.6 MB
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  Actions
  - Deepak Gupta @ Ben Cowden on Oct 16, 2012 1:55 PM
    Mark Correct
    Correct Answer
    Ben you need to include all the parts files too to check the issue. To include all of them, open your assembly and pick Pack and Go from the file menu. There you would find the option to zip all the files. Once you make that zip file, upload that here to check.
    Like • Show 0 Likes0
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    - Ben Cowden @ Deepak Gupta on Oct 16, 2012 3:41 PM
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      Correct Answer
      Hi Deepak,
      
      Here is the zipped Pack and Go file.
      
      Thanks,
      Ben
      Attachments
      BCowden.CPendula.zip2.5 MB
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      - Deepak Gupta @ Ben Cowden on Oct 17, 2012 11:01 PM
        Mark Correct
        Correct Answer
        Ben, I'm not sure as what is the reason as I'm able to add them. The only difference is that I'm using SW2012/SW2013 and unfortunately I don't have SW2009 to exactly figure out the issue. So if you send these file to you VAR or someone one the forums who has SW2009 Premium might be able to help you. Sorry for the not being able to help out.
        Like • Show 0 Likes0
        Actions
Jim Boland Oct 28, 2012 5:35 PM
Mark Correct
Correct Answer
The problem here is your basic understanding of how animations are calculated. In an Animation motion study, all motion is based on descrete postions at descrete times, in other words Key Points. There is no physics involved and the component motion is determined by the distance and time between points and the frame rate. Parts can move through each other and they can move with infinite velocity and acceleration.

In Basic Motion and Motion Analysis type studies, the components must follow the laws of physics. The only key points for components are the key points a time zero as these are the intitial position for each component. Once the calculation starts, the solver moves ahead a very small time step and calculates the postion of all components based on the motion drivers (forces, torques, gravity, motors, etc) and the joints (mates). This continues until the end of the study. You cannot add key points for components as that would not make sense in a physics based solution.

If I understand what you want to do, you can take your intital motion study and duplicate it. In each study, move the timebar to zero and then move the individual pendulums to the starting positions you want and calculate the sutdy. This way, you can have many variations of the pendulum motion.

Also note that the fact that you cannot add key points to components in physics based studies is documented in the only book devoted to creating animations "Creating Animations Using SolidWorks" available from the SolidWorks merchandise store at http://store.solidworks.com.

Also note, that while it does not apply to your problem, physics based results can be used in animation motion studies by importing the results of the physics based solution into an animation motion study using the Animation Wizard.

Hope that helps.
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Cannot add key points in Motion Analysis?

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