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Sketcher and splines V14?

    
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Paul

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Message 1 of 9

 Sketcher and splines V14?
14-01-2009 07:44 . pm   |   View his/her posts only
Hi Mike,
are there any improvements in the way splines are created and edited in V14. Sketcher especially.
Do we get visible points? clik and drag curve or points? Can we edit curve type after creation?

If you have a cool video of new sline stuff I'd be keen to see it.

Cheers

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Mike

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Message 2 of 9

23-01-2009 05:04 . pm   |   View his/her posts only
Paul,

There is nothing new to the software but there may be somethings you are unaware of. As I have stated before, V14 has a DRAG command. This works on Splines as well as other geometry. It will snap on the defining points if you so choose. You can also use the lightning bolt to auto constrain, then adjust the dimensions of the defining points.
If you right-click on a spline we have the MODIFY command whic allows you to adjust the control points of the spline; display the curvature comb and a Local/Global switch that controls how much of the curve will move when a point (any point on the curve) is modified. You can Lock/Unlock the position or tangency at any point while modifying the curve.

Another technique to concider when inserting a spline is to insert points first, then insert the spline thru the points. I think this just gives you a more visual method for seeing the defining points.

By "curve type" are you referring to the degree of the curve...Yes. All in V13.

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Paul

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Message 3 of 9

26-01-2009 06:25 . pm   |   View his/her posts only
Thanks Mike,
FYI. If I am working on a spline as a design element I create a solitary point independent for the origin then auto constrain sline points to the this 'free' point, allowing the entire spline to be relocated and retain the shape.

If I choose to RMB drag modify a spline point, the screen updates but the exisitng dimensions or constraints take over again and the 'visual' mods are lost. So the two methods are not compatible.

Create a set of points, constrant then and 'critical locate the spline points on the placed points. Do a constaint check and it is all OK. No observale constraint other than the orignal point dimensions etc. OK until you RMB modify the curve using RMB when all the point connections are lost!

So in one case the constraints rule, in the other, the modify destroys the constraints. Apart from that there is the old 'implied constraints' not being visible problem. How is one to know what is the nature of the constrain if the implied constrains are not visible???

'Curve type': In 2D there is no opportunity to edit the fairing type.(Degree is fine) You have to redraw a new curve, constraint etc etc. Yet in 3D you can edit the fairing....

I am never sure is RMB modify end point tangecy/lock tangebncy works. IMO the lock doesn't lock, but what is the definitive test when one methed breaks constrains and another does not.

IMO most 2D splines need some constraint to start with e.g end points - locations and tangency then the shape is tweaked. Yet it can be difficult getting a spline to behave in a controlled and reliable manner.

These issues apply to open and closed splines 2D.

I use Corel Draw and find its spline management options to be consistent and easy in comparison. As you edit you can see all the sline pint and influence info. Thats a great help.

So my opinion remains the that VX 2D spline editing is vague and clumsy and is open to some improvment.

Am I alone in this opinion????

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Mike

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Message 4 of 9

15-02-2009 12:11 . pm   |   View his/her posts only
Paul,

I guess it is like drawing a line, constrain it, then trim it. Trim is going to have to ignore your constraints or it just wouldn't work.

There is no advantage to drawing points first then drawing the spline as opposed to just drawing the spline except if it is a long spline you can break up the insertion of points, take a break, go to lunch, coffee, surfing then continue. Typically, if you use points or just draw the spline to absolute coordinates and constrain it, I would think you would want to adjust the dimensions to adjust your spline. The RMB - modify was created to tweak the shape of your spline before you create your constraints.

I don't see that "implied constraints" being invisible is all that bad. Imagine drawing a rectangle and each corner has a horizontal and a vertical constraint visible. A mess, would be an understatement.

Quote

I am never sure if RMB modify end point tangency/lock tangency works.
The definitive test is easy. After creating the surfaces from your 2d geometry, INQUIRE - Face - Continuity Error and pick the edge between the two faces.

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Paul

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Message 5 of 9

15-02-2009 04:28 . pm   |   View his/her posts only
Hi Mike,
several points (no pun intended) in reply.

Implied contraints are used by the solver, so when an otherwise doable sketch will not solve, the user is left wondering what are the implied contraints I cannot see that are causing this lock up.
I have found this is most likely to occur if I use a predifined i.e. rectangle) shape element then trim it to other lines/curves with Smart trim. As far as I can figure, Smart trim also applies the invisible constraints Just maybe it would be helpful to have some way of seeing all the cards on the table.

Curve through placed and dimensionally constrained points, the implied constraints keep the curve attach to the points during and after point dimension changes. If I do a constraint check the line show as unconstrained. Now I do an auto constrain (no visible changes) and check and it is shown as fully constrained. Cool.
I do a RMB modify and the previous constraints are dropped!

Now if I do the pointless (thru point) curve and auto constrain, I can see all the constraints. A con. check shows fully constrained. I do a RMB modify and the curve ignores the constraints. I then do a contraint check and it's OK. I do a regen and the sketch moves off to its own position somewhere beween the original and the modified depeding on the constraint types. This is becuase the through point has now converted to a control point.

It all gets a bit confusing as to how to control a curve.

I note that spline to line tangency is added in V14 at last which is great.

Now if the closed spline will remain tangent during RMB modify as well we might be moving forward! (Note this is a problem when you move the start or end points only)

In summary, I repeat my ealier comment, that curve management needs to be significantly improved in sketcher.
It remains to be seen if this has been achieved in V14.

Cheers

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Paul

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Message 6 of 9

15-02-2009 04:51 . pm   |   View his/her posts only
Hi Mike,
one further comment (for now).
I acknowledge , not everyone does design with VX. however for those who do and are madly in love with curvey stuff, spline management is sooooooo important.

I recently saw a video demo of another software (can't remember which) that allowed you to tweak the spline in model space and see the changes to the model surfaces previewed before committing to the changes - now that is nice. It was just a click and drag anywhere along the spline.

It is important!

Cheers

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Mike

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Message 7 of 9

16-02-2009 09:07 . am   |   View his/her posts only
Here is a suggestion. Since V14 has a completely new sketch solver, let's agree to hold this conversation until you have seen it. I have given you a preview of the new INQUIRE constraints command. It has been enhanced even more since then but in my opinion it is leaps and bounds better than before.

I just found this out myself this morning; the only implied constraints (invisible) are end point constraints. We have two. Points Horizontal and Points Vertical constraints. This includes all the end points of a spline.

Quote

I have found this is most likely to occur if I use a predifined i.e. rectangle) shape
If you are referring to READY SKETCH there are a couple of things you may not know. There are constraints that are blanked. Use Swap Entity Visibility to see what we have blanked by default. Typically you don't need these to update a READY SKETCH. Second, if you place a READY SKETCH at any location other than (0,0) there is an anchor constraint at the origin of the Ready Sketch that needs to be erased.

Quote

It all gets a bit confusing as to how to control a cureve.
Just remember our one rule: If you constrain, change the constraints!

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ChrisWard2k2

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Registered: 2011-11-22

Message 8 of 9

16-02-2009 12:44 . pm   |   View his/her posts only
If you place a ReadySketch anywhere, it is constrained about it's own datum point. That point should not be erased, but the point at X0 Y0 which is inserted by the system on Sketch creation can be and often should be.

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Paul

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Registered: 2011-9-17

Message 9 of 9

16-02-2009 06:18 . pm   |   View his/her posts only
Hi Mike,
agreed.

This is almost spiritual. How can I really discuss elements I only imagine or who's exisitence is implied, as I have never seen them. I guess that is what gurus do???

Absolutely looking forward to V14. When it finally arrives ....

Be assured I will be giving the spline tools a session to see if the changes have resulted in a more predicatable and intuitve experience.

FYI I seldom use ReadySketch. No real need for premade shapes AND the colour of the constraints is not good for light backgrounds!!! Otherwise the times I have used it sucessfully it has been good becuase it has the constraints all done.

Cheers
Paul
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