Vred Python position constraint on only one axis

[Anonymous]

Good morning everyone.

I have a problem with Vred's Python constraints. I'm trying to make a slider crank mechanism (in figure), and to do that I'd have to make the blue slider follow only the position along the x-axis of the white skid, but maintaining the same position along the y-axis (in order to remain in the red slider housing).
I haven't seen any option to be able to constrain only one axis in the python commands for the position constraint. Is there a way I'm missing?

[Christian_Garimberti]

Hi Gianmarco,

could you share also the model?

I don't think there is an option, but maybe playing with more then one constraint it could be possible.

This could be a good challenge to try!

Best

Chris

[Christian_Garimberti]

Hi, i'm trying but until now i have not found a combination of two or more constraints to solve the problem.

Just a question...

You want to use constraints because you have to interactively move the mechanism? Or just to have an animation of it?

Bets

Chris

[Christian_Garimberti]

Hi Gianmarco,

i give up... 😅

thinking about this behavior i remembered to ask in this form something similar.

https://forums.autodesk.com/t5/vred-forum/block-rotations-or-translations-on-some-axis/m-p/8953019#M...

I think the only way is to have that functionality.

Unless you want, or can, create a complex animation with keyframes to keep the mechanism in the correct position.

But being not linear movements i think could be very difficult.

Best

Chris

[Anonymous]

Hi Chris,
Sorry I couldn't answer earlier. I'm attaching the model in case you would like to have a look at it. In any case yes, I would like to impose the constraints in order to have an interactive response from the mechanism, because a "simple" animation is not enough for what I want to do, unfortunately.
In any case I thank you for your availability and kindness.
I also had a look at the post on the forum you indicated, hopefully they will soon add this new feature for rotations and translations.
Thanks again,

Gian Marco

[Christian_Garimberti]

Hi Gian Marco

Thank you for sharing the model.

I will give another try in my spare time, maybe using some constraints and some other python scripts

Best

Chris

[Christian_Garimberti]

Hi Gian Marco,

working on your model finally i found a workaround... it is not perfect, and maybe it could be better. maybe some other peoples on the forum could give some advice.

Attached the scene.

After opened, press S to start the animation. The animation is just to show and test the mechanism. atret that, if you rotate the "connecting rod", everything should works as expected.

E to stop everything.

It is not perfect because of the refresh. I used the world transformation of the Blue Slider (the Z translation) to keep it at the correct position. i tried wit a vrTimer or a dedicated Class to update the position every frame. It is not perfect because, depending on the speed of the movement, you could see a little bit of shaking or translation.

The slower is, the better is.

Waiting for an official API, this could helps.

Best

Chris