VX Sketcher issues

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Kevin

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Registered: 2004-4-26

Message 1 of 13

 VX Sketcher issues
01-07-2004 02:47 . pm | View his/her posts only
I admit I'm new and as yet untrained, but I have been a SW user since 97, a ThinkDesign user since 2001 and various other systems so I have managed to pick up a lot from the training manuals....but.....I have issues with the sketcher.

In every other system I have used if I fully define a sketch then drag (move) a line, say, the entities attached to the dragged line will move and stay attached - not so in VX. Why? It appears after much experimentation that only changing dimensions will keep the sketch intact. After the free and easy methods of SW and Think I'm finding this behavior a bit had to handle. As a designer I sometimes prefer not to fully define a sketch but drag the entity visually.

I'm just wondering do I have this behaviour all wrong, or if I am correct why is VX built this way considering it is aimed so much at the ID market. And will this be changed in v10?

To see what I mean, create a square (4 lines), autoconstrain it then drag (move) one of the lines. The end points break the attachment. Surely this can't be right? Is this just down to there being no end to end constraint (no pun intended).

Anyone?

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Kevin

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Registered: 2004-4-26

Message 2 of 13

02-07-2004 12:48 . pm | View his/her posts only
One more thing.

Although the stretch tool is intended (I assume) to cater for the entity dragging it does not work for tangent constraints.

For example. In sketch mode, select the standard slot tool and draw a slot. The constraints are automatically applied. Now use the stretch tool and select one end of the slot (arc and line tangent points) and move to a new location. The tangency breaks up at both ends.

Unless someone can explain the logic of this behaviour it seems to be both unintuitive (particularly to other CAD system users) and wrong. In every other system I have used when I drag a circle or arc with a line tangent constraint set up the tangent condition always holds no matter where I move the circle to.

This is kind of worrying behaviour to me as a new user, and after wading through the tutorials, cad reference guide and online help I'm none the wiser. How do I set up a constrained condition between two (dofferent radii) circles with tangent connecting lines so that when I move or change one of the circles the tangency for the lines stays intact?

If anyone can explain how this works then I'll be happy to create a demo movie for you to post on the website!

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Kevin

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Registered: 2004-4-26

Message 3 of 13

02-07-2004 01:23 . pm | View his/her posts only
To demonstrate my issue I've atatched a shockwave demo file using the standard slot as an example. This is as basic as it gets.

Note how the sketch is fully defined, but when the points are stretched the previously applied tangent constraints get broken at both ends.

Like I said, this worries me.

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ChrisWard2k2

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posts: 2

Registered: 2011-11-22

Message 4 of 13

02-07-2004 03:48 . pm | View his/her posts only
Hi Kevin

VX's Sketcher uses our own code. It is a little different to the other applications you mention (most other systems bolt-on the Sketcher from D-Cubed UK). The dynamic non-dimensional dragging that those systems offer is slick, but that plus is also a hindrance because large entity count sketches have poor performance.

In your movie, the Sketch constraints go pear shaped because you have moved entities in a manner that does not respect the constraints you have laid. If you had constrained the shape differently (as has been done in the pre-constrained examples found in my VX DAL program ReadySketch), the shape would have been fine - and guess what, you can break SW and Think3 Sketches too! If you move an entity in a legitimate direction in accordance with a Sketch's constraints, the Sketch does not update dynamically but you only have to hit the re-solve (re-gen) button and hey-presto.

Sketch constraints do require some thought at times. The VX Sketcher is very powerful and boasts good performance for complex Sketches (even faster in VX v10!). What impressed me from day 1 was the ability to have several fully constrained shapes all in one Sketch. Plus of course everything from the entire Sketch down to just one entity is accessible to the modeller - fantastic power.

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Kevin

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Registered: 2004-4-26

Message 5 of 13

03-07-2004 07:44 . am | View his/her posts only
Thanks for the answer Chris.

I can see where you are coming from here but my point is that if VX Corp is expecting users to migrate to VX from other systems this sort of behaviour is fundamental to the transition process, in my opinion. Just because VX does not use the standard sketcher modules from D-Cubed does not make it bad, of course, but it does require additional education for new users within the help system to explain this better.

I think it would be a very worthwhile exercise for VX to create some simple screen movies (like mine - only took 2 mins) showing how to set up sketches for common cases.

My example I think is a reasonable one. You say that I did not set up the sketch correctly. Perhaps, but if I use a standard tool, and use the autoconstrain I would expect the constraints to be applied correctly surely? Why also, when the initial tool applied tangent constraints were these broken by the simple act of moving? To my mind it is logical that is a skecther displays a constraint condition then these should be always applied. To my mind if these conditions break the sketcher is incorrect - ie - buggy.

Perhaps someone in VX could repeat my example showing exactly what to do? I think this would benefit a lot of new users. Once I see this for myself I will understand and I would be more than happy to do further examples to assist other users starting off like myself.

Kevin

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ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 6 of 13

03-07-2004 08:55 . am | View his/her posts only
Hi again Kevin

The auto-constraint of the Sketch was effectively one of several solutions - of course, the system does not know what the User is going to do next in this case, so the constraints applied turned-out to be the wrong choice. I too thought the help could be better - but then, for each scenario, there are so many possibilities, we could end-up with Sketch help being more lengthy than all the other subjects put together

The best way for Users to be both productive immediately and at the same time have a wide range of examples, is for us to supply a library of pre-defined Sketches for popular every-day shapes. I have built a large library, with an easy to use interface to access it, called ReadySketch. ReadySketch has precisely the solution you require for the "slot" example. It will be built-in to a future release of VX.

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Kevin

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Registered: 2004-4-26

Message 7 of 13

03-07-2004 09:30 . am | View his/her posts only
the joys of Saturday working :-(

The one thing that worries me about libraries of sketches are that you never get the one you want! I'm basing this in the ThinkDesign Smart Features which included literally thousands of sketch set ups, but in 2 years of using Think I used them perhaps 3 or 4 times total. the rest of the time I created the sketches from scratch - it was quicker. The simple fact was that the sketch library was used as an excuse for deficiencies in the Think Design sketcher (and there were many!).

Which brings me back to VX Sketching. I'm a bit worried about the comment you make about the sketch help requiring more pages than the rest put together :-)

Dynamic sketch dragging is (to my mind) a red herring anyway. I switch it off in other systems and use the rebuild instead. My worry as regards this particular example is that there was no rebuild/update option. The constraints just simply broke.

As I said I would really like to see 2 demos from VX.

The slot I did - how to constrain it properly AND show how to edit it properly.

2 different radii circles with two tangent lines and all trimmed up to make a single closed profile (I can't figure that one out at all - every attempt I make just fails).

The bottom line is that I'm no newbie to 3D parametric CAD. I've trained many users over the years formally and informally. I've even done demos at shows.

These simple scenarios should not be that difficult to set up. But they seem to be.

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ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 8 of 13

03-07-2004 10:41 . pm | View his/her posts only
Hi Kevin

The attached is one of the ReadySketch slot sketches for you to study. I think my library is more pertinent than Think3's, because it has been put together by a designer who knows what designers want. The GUI is very accessible too. Also attached is a modified version of the original sketch which meets your description (tear drop shape). ReadySketch has a tear drop Sketch. This slot type would normally be used with vertical orientation (as a fastener slot for example). The attached version is however rotatable. To modify a parallel slot Sketch to produce a tear drop:

1) Erase the parallel line constraint pair and slot width dimension;
2) Insert radius dimensions for each arc;
3) Iterate the dimension values to give the exact size desired.

There should be very few occasions where a rotable Sketch shape is needed - simply orientate the Sketch Object accordingly at time of creation, such that the Sketch shape can be horizontal/vertical within the Sketch Object.

ScreenShot

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Kevin

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Registered: 2004-4-26

Message 9 of 13

04-07-2004 06:58 . am | View his/her posts only
Thanks for that Chris!

I've had a look at this now and it is becoming clearer in that you appear to have to set up datum constructions to reference dimensions off before creating the geometry? Also do I assume that VX sketches are only really editable by altering dimensions and using the stretch tool is primarily for a shape adjustment before setting constraints?

One more question. Where do I get this ReadySketch app now, or when is it getting integrated into VX? Also will it come with enhanced help files for explaining how each sketch was set up?

Thanks again.

...and folks I don't normally work all weekend - well only every second one at the moment

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ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 10 of 13

05-07-2004 01:07 . pm | View his/her posts only
Hi Kevin

You can apply the stretch tool on a constrained Sketch. If your stretch action/direction does not comply with the constraints, the system assumes that the constraints affected are not required (i.e. they are being "over ruled" by the User), so careful picking of the points and definition of stretch direction is required. I think the stretch command is of limited value since you can place a dimension and modify the Sketch parametrically in less time.

The Sketch I have attached has it's own ref geom to allow a parametric rotation. Obviously, this is not often necessary.

I don't know exactly when the development team will be able to integrate ReadySketch. It exists as a working add-on program that is run in VX via the User menu. (In the same way as other VX DAL programs, see the downloads library, http://support.vx.com/customers/macros/ ). I have asked the powers that be if we should add it to the downloads library as a freebie.

ReadySketch does have built-in help about it's GUI, but it does not provide instructions on how every sketch was built. I think most Users will not be concerned about how the sketch works, they just want to use it However, I think those that are interested will gleen a lot by simply studying the Sketches.

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Robert

Newbie

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Registered: 2011-11-22

Message 11 of 13

06-07-2004 05:29 . pm | View his/her posts only
Hi Kevin, Hi Chris,

I hope to see ReadySketch integrated into VX version 11 but in the meantime, we'll make it available on-line and also on our installation CD.

Thanks,

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ChrisWard2k2

Newbie

posts: 2

Registered: 2011-11-22

Message 12 of 13

06-07-2004 08:18 . pm | View his/her posts only
OK everybody, Bob has decided to make ReadySketch available for free, and it is available now : http://support.vx.com/customers/macros

Hope you find it to be useful.

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Kevin

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Registered: 2004-4-26

Message 13 of 13

07-07-2004 04:27 . am | View his/her posts only
Great news guys!

Many thanks for the rapid feedback. In return, when I get a free moment (and when I understand the processes fully) I'll try and post up some movies of sketch/constraint issues for new users (especially those coming from other systems).

See also