Translate Curve Points

How can you translate the unique parametric vertical points below onto another curve? Each vertical below has its own unique parametric points that I need to translate / mirror to its edge curve in +/-y direction?

Can you sketch where you want the new points to be? I feel like you want them along the left and right sides of the surface, but can’t confirm.

If that is the case Curve.PointAtParameter should do the trick.

Hi @jacob.small,

The points will be in the longitudinal direction:

Yeah - Curve.PointAtParameter should do the trick.

Assuming you know the ‘post’ locations as parameters, it would be something like 0..postParam1..#cnt;, then postParam1..postParam1+(postParam2-postParam1)/2..#cnt;, then postParam1+(postParam2-postParam1)/2..postParam2..#cnt; and finally postParam2..1..#cnt;.

From there it is just a matter of merging the first post point list reversed, the first post point list, the second post point list reversed, and the second post point list. Flatten those and the Curve.PointAtParameter list and you should be good to go play connect the dots.

Note that cnt should be 1 more than you have post points so you don’t have a vertical connection from the post to the bridge right under it.

Give it a shot and post your dynamo graph if you get stuck.

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Hi @jacob.small,

I have the post locations as coordinates with X and Y constants on the vertical line. Z varies at a step of 15. What would be the postParam1?


@jacob.small…Would breaking-up the nurbscurves on each edge side into two parts be easier and then generate the same count of points?

How did you generate the post in the first place? I had assumed you built the posts via parameters along the curves; if not post your graph showing what you have built so far and I’ll try to have a look.

@jacob.small…here is the graph:

BridgeExample.dyn (83.6 KB)

Here’s how I’d go about building a single center support version:

Now you’re looking at edge supported instead, so there are some changes to make around which curve you drive your points from, but it should serve as a clear example on how you could build a graph to get results like this:
Parametric Bridge

From here the next logical step is to build an evaluation setup to determine which layouts perform best, and send them onto Generative Design for optimization. Honestly the ‘evaluation’ part is the difficult bit here; don’t try to do full finite element analysis, but instead build the formula for a rule of thumb calculation and let that guild your optimization

Best of luck in your exploration. :slight_smile:
Parametric Bridge.dyn (74.7 KB)


Hi @jacob.small,

This is what I was trying to get to! The pylons at the deck center is preferable and more efficient. Thanks alot🙏

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Parametric Cable Stayed Bridge Harp System setup for Generative Design. Credits to @jacob.small👍

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