Question from the Shapr3D team: editing curves

Now we are going to work on the curve editing feature, that is (at least I think) the last really painful missing feature from Shapr3D. Regarding that I have a question for you, and if we could collect lots of feedback on this, that would be really nice.

The question is BSplines.

Currently you can create BSplines with interpolation. How about we dismiss this approach, and we would go with control points?

I think this is the way to go.

I’m cool with B-Splines. Though, Bezier with control handles would be nice too. :slight_smile:

They would be still BSplines. The difference is only how you define them, by control points or interpolation.

I find the splines line quite difficult to control so don’t use it very often. I like the sound of control points - would I be right in thinking you can drag a control point to make it either curved or leave it as a sharp corner? If so, this would be really good.

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I like the current approach, but i really miss tangency handles. I find this method easier to get the exact shape i need. But sometimes the control points method is nice to have too. So why not make both available, like most cad apps do.

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Great news: in the next release you will be able to edit curves after you created them. :slightly_smiling: (Better late than never ;))

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That sounds great Istvan - looking forward to it. Will it involve moving points on the curve only in the orginal plane that it was drawn in (x,y) or also ability to move points in the z direction? Andy

Currently only planar curves are supported, but we will probably add 3d curves later

That’s great - thought it was worth asking! Many thanks for all the great work you guys are doing on this app. Andy

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Fusion 360 only allows curves through fit points I as a designer I hate it.
The main reason why I think it is junk is that with more fitpoints you change the complete curve when editing one fit point.

Thus in fusion I only use it as a blend curve or max 3 fit points.

Honestly with a cv curve like right now you offers better abilities to sculpt curves in a more predictable manner.

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@Istvan_CEO_Shapr3D

Hello, I am attempting to achieve some results with curves. I thought this case study might be useful from an engineering perspective. I am attempting to re-create this airfoil shape that is at the root of a wing that I have already built a prototype of. I like the way it flys and I do not need to change or play with the airfoil at this point. I just want to draw this profile and then attempt several different types of lofts on it to recreate my wing so that I can play with other design aspects. I will attempt to load a picture of the measurements so that you can choose if you like to speculate the best way to reproduce it in Shapr3d. There are no guides or measurement tools in Shapr3d to perform a layout so I used lines to delineate at the chord and where more resolution was needed every 5mm. There are no measurements where a smooth tangential curve is good enough. I found it quite difficult to create with confidence a curve that made close contact with the points I had outlined in Shapr3D matching my planform. This type of curve that has a pre-determined parameters is going to be very common for many facets of engineering. Creating enclosures that are organic yet still allow for specific bodies of space to be void with very tight tolerances is paramount to many high end projects. I wondered if this might help in your software design process to consider this small project. Maybe I am just going about it incorrectly but an updated curve system that helps signify when lines are tangent amongst other control aspects may come in handy. An initial idea of mine is that it might work to have splines that are connected change to a matching line color when tangent. The section of lines that are not tangent would be two different colors but when the meet and are tangent they would match. Does that make sense to you?

BTW those measurements are just rough constraints, the point is not to conform to them exactly but to use them as min and max constraints. The real goal is to know that I have a really smooth flowing line while matching the criteria closely.

Well, I think we should add a “spline with tangents and points tool” when we will implement the advanced curve editing tools, it would probably help, right?

Absolutely. I was able to get a nice shape last night with what is available. After getting it though I still want that confirmation that everything is smooth and tangent. When you send something to a machine and you’ve got that surface in front of you deformities start to show up. Not to mention the effects in flight.

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If what you make is not confidential, it would be really helpful if you share some of your creations here:
http://discourse.shapr3d.com/t/share-your-creations/?source_topic_id=60

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Control points with options to join and trim would be an excellent addition.

Yes, advanced curve editing is coming in the next few weeks.

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You started actually in a good and right way, when I create a shell for an Apple iPhone product I do not get a curve to work with but X and y points through which a curve has to run through.

You could scan in an image and zoom but then the line will get bigger and thus be less precise.

It is in deed labor intensive to recreate such curves.

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It looks a good bit like a kiteboarding hydrofoil cross section…

Your idea of lofting will work until you reach the end of the wing…I don’t think lofting will work there.

Did Advanced Curve Editing make it into the product? I am looking for better control on splines I have created. Adding/removing/converting control points, etc. Is that supported?