Bezier Curve tool help?


#1

Hello folks, I have downloaded the Bezier Curve tool and have been playing around with it. Thanks Dave for the info on this tool.

I have attached a pic of what I am working on, it will be a base for a trestle table. I have made guidelines where I want all the curves and I can seem to do what I like, but then I cannot duplicate what I want on the other side to be exact? I have done just on the one side then cut it in half and moved it over and flipped along the red axis and then just rejoined it, but I would really like to know how to duplicate the curves to be able to always recreate the exact dimensions of the curves I like.

I hope this makes sense? I continue to try to find videos on this, but you guys always seem to be able to cut my research time in half!

Thank you so much as you guys are always so helpful to us new guys!!

Jay


#2

That is actually the fastest and easiest way to guarantee that you have accurate symmetry. Drawing anything twice takes more effort and risks making small, subtle differences.


#3

You can select the curve, copy and move, make a group or component which saves it for use again later…flip it. place it where you want


#4

If you are going to use the basic shape of that foot in future projects, save the whole thing as a component. You can modify it as needed in later models if you want.

If you are going to save it for later use, make it a component not a group.

Another way to copy the curve to the other end.
curve


#5

OMG!! Dave you are a magician!!!

Thank you guys!!

Jay


#6

I think he wants to know how to duplicate the method of making the curve rather than just copying it and flipping it. I wouldn’t know how to do that with a bezier either.


#7

You could make a component of the Bezier curve if you want and save that. I suppose you could make a collection of Bezier curve components as you might other components. I’d be more inclined to save the foot component if I thought I’d use the same basic shape. If the arc on the bottom was drawn correctly, it would be easy enough to modify the component while keeping the end curves the same. Or, it’s simple enough to remove the arc on the bottom and replace it with a different curve. Maybe save the component without the arch on the bottom.


#8

Thanks again!! a BIG help!! This is the table been working on and the bench will go with it.

Jay


#9

#10

This will sound silly, but you just do whatever you did the first time again. You just have to make sure you set up the control points exactly the same (or mirrored/flipped). But as several of us have pointed out, that is the hard and inefficient way to go about it. Whenever you have something already drawn, don’t draw it again, just copy it!


#11

Thanks again guys!!! Such a big help!! Sooooo much to learn!! :):slight_smile:

Jay


#12

Which is why I suggested he save the “the special curve” as a component which can also be scaled to a smaller version to be use in other members of the build like the one illustrated in his stacked base on the table.
Well I learned some things anyway. I suppose a “signature” curve would be something a designer or maker might find desirable but as far as I can see there is no real easy formula to make such splines for the average modeler. The lesson was timely for me as I just started using the spline tools myself.
Arcs are more defined. Beziers are artistic or loosely defined. Would that statement be true? I think as a wood worker defined arcs would be easier to exact than a bezier. I missed the part of this thread which led to the use of beziers in the first place.


#13

There are a lot of variations on Bezier curves (aka splines). Unlike arcs, which are sections of circles so quadratic, most splines are constructed using cubic curves. Splines are constrained by a collection of control points. Depending on the kind of spline, the curve may pass through the control points or be “pulled” toward each control point while forming a smooth shape. That lets them create more shapes than circular arcs but also makes them more complex, which can sometimes be confusing until you become comfortable with them.

One of the neatest uses of a classical Bezier curve is to generate a shape that blends smoothly between tangents to two lines. In the following animation I pick the end of one line, the end of the other line, and then set the middle control point at their intersection. As you can see, this creates a curve that is tangent at the end of each line and sweeps smoothly from one to the other (the UI is a bit different from the EW Bezier because I used Fredo6’s extension, but the math is the same):

classic%20bezier

If you extended a line until it reaches a third one and repeated this process you would have a smooth curve that is exactly continuous at the original end because it is tangent to the line coming from both directions. That way you can blend together multi-line shapes, including in 3D with perfect smoothness. The equivalent is difficult or impossible to accomplish using circular arcs.

bezier%202


#14

Thank you for taking time to illustrate.


#15

Your table design made me think of a pilgrims shoe.


#16

In addition to the other methods suggested, you might try using symmetrical components. In your case, this is ideal since you want a mirror image of the result.

2018-03-09_17h13_00


#17

Wow thank you guys! So appreciate all your efforts to help a newbie!

Jay


#18

This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.