what does this mean: " sketch is fully constrained"

[cekuhnen]

I followed the video also activated preview sketch in preferences but cannot replicate the same visual color changes for sketches.

How is this supposed to work? The video does not really explain the ideas behind it very clearly. It mentions great feedback but what feedback?

[jeff_strater]

Fusion added an option to color the sketch geometry differently once it becomes fully constrained (a much-requested feature).  To turn it on, go to the "Preview" page in Settings.

It's a "preview" mostly because it still is in development.  But, I use it all the time.  It is not 100% perfect yet (for instance patterns don't really show as fully constrained when they should, etc), but I find it works really well in the most common cases.  Give it a try...

Jeff Strater (Fusion development)

[cekuhnen]

Jeff in the first post I stated that I have this already activated but fail to understand what you guys define with "fully constraint".

Also I followed the sketch video and my lines remain blue no matter what I do.

[StephenWolf]

Claas: To follow up on the point you're making about the video, could you let us know which one you watched? If there's an issue with the content of the video, we'll make sure to fix it.

Thanks.

Stephen

[jeff_strater]

In order to be truly fully constrained, you have to ground at least one point on the sketch.  For instance, if I have this:

The sketch, though fully dimensioned, is not fully constrained - you can still drag it around on the sketch plane.  However, if you ground one of the points, then it is fully constrained (and notice the color change):

Jeff

[cekuhnen]

I guess here is the logic I have a little issue with:

so here is a sketch everything is constraint so it cannot move

in addition there is also an x and y distance established to the sketch xy 0 point.

so I cannot move the sketch at all but it is not fully constraint.

now adding also a fix point finally makes the sketch fully constraint

removing the dimensions that related to the sketch and sketch center point breaks that fully constraint status

the logical question I have here is then this:

why do I need to have a x y dimension to the sketch center point +  a fix constraint to make a sketch not movable?

each approach alone should be sufficient already?!

if I dimention all edges and relationships + fix one point 

or

if I dimension all edges and relationshios +  relationship to the sketch xy 0 point

should that not be enough?

This for example is hardly covered in detail in the new sketcher movie at:

http://fusion360.autodesk.com/resources/akn/view/NINVFUS/ENU/?guid=GUID-D701BB8F-6FAB-4282-B248-6206...

That type of information is what should be elaborated on. but the video feels more like a run down of how sketching works in general which is not new content.

[daniel_lyall]

silly question how do you ground a drawing never had to do it so dont know how

[HughesTooling]

I don't see the way this works now being very useful if you have to have a ground point. This sketch is fully constrained with dimensions but shows unconstrained until you use a ground point, but then you can't drive the rectangles position with dimensions, not very helpful. It would also help if there was a colour change when the size is constrained but the position isn't. So in the example below, have a colour change when the 35 and 20 are added to the rectangle then another change when the position is constrained.

Thanks Mark

[daniel_lyall]

---

@HughesTooling wrote:

I don't see the way this works now being very useful if you have to have a ground point. This sketch is fully constrained with dimensions but shows unconstrained until you use a ground point, but then you can't drive the rectangles position with dimensions, not very helpful. It would also help if there was a colour change when the size is constrained but the position isn't. So in the example below, have a colour change when the 35 and 20 are added to the rectangle then another change when the position is constrained.

Thanks Mark

---

if this stop drawings from being driven by dimensions what is the point of it, it`s silly sorry if I sound rude but most of what I draw is for woodwork so not being able to change a demantion becouse it needs grounded is not usefull at all.

[promm]

daniel_lyall,

There are several different design workflows where you reference geometry from other components and models.  It is important to have your sketch referenced to your origin for referenced geometry to parametrically update and behave in an expected manner.  Having to reference the origin in order to be fully constrain is a practice that is use in all the different CAD packages I have used over the years including Inventor, SWX, Pro E...  Some CAD users start their sketch at the origin as a way to reference the origin without having to dimension to it.  I have some experience with woodworking as well and would be happy to set some time up with you next week to show the benefits of parametrically updating models.

Cheers,

Mike Prom

[Anonymous]

From my experience, fixing/grounding points are useful for two things.  Either to temporarily hold a point/geometry from jumping/doing something wild when say editing a dimension, after which the grounding can be removed.   Or as a quick way to lock down a sketch from possibly sliding around from later unusual modeling operations (but as observed is best to have desired dimensions in place before locking down). 

Jesse

[cekuhnen]

Promm, I think the problem here is that the new update information is insufficient for new users but also for advanced users like me who never used this feature before - never needed to in other CAD apps.

With a video specifically explaining what the philosophy behind grounding a sketch is and why and how to use it would be very helpful.

[Anonymous]

For the time being I'm not going to use/teach the experimental sketch constraint color indicator, unless find a need to, since from my experience I've not really needed such indication to begin with, and if there are some cases where it's not indicating accurately, such as where Mark and Claas demonstrated, it may be confusing to use in general.

So Daniel, to answer your point, as I indicated in my last post, normally there I've found no reason to use grounding points.  Although as Mike points out, having a single grounding point for a sketch geometry, such as to the origin, can be useful to insure proper positioning of the geometry, such as after a dimension is altered.  The reason Mark's center point rectangle lost the ability to modify the dimensions once a corner is grounded, is because the center of the rectangle was also dimensioned to a second grounding point, i.e. to the origin, preventing the freedom needed for the center point rectangle dimensions to subsequently be edited. 

Jesse

[Anonymous]

Claas, when you dimension the x and y position (or distance and angle) of a point to the origin (which is grounded), you are effectively "grounding" that point (the main benefit being it will now not move relative to other points in the same sketch or others that are also grounded).  Applying the Fix constraint is simply a slightly quicker way to ground.  

Jesse

[cekuhnen]

What I struggle right now is grasping the logic the solver follows:

Below two lines are white beccause with the other constraints and the sketch center they are locked down.

Adding a dimension left locks the top edge down - so now you cannot stretch the sketch left and right anymore

because the arc and the vertial dimensions lock the width in place.

but why is the right edge not white from the beginning? It is constraint as well!

And why is the bottom line white while there is no constraint that defines or restricts the left and right movement/scale

[cekuhnen]

so here is another test runs and I must say I really have a hard time to fully graps what qualifies as fully constraint and what not.

Upper right is but lower left is not? confused here ...

[HughesTooling]

Surely the lower right picture is over constrained, do you get an error with 4 dimensions and an anchor.

Mark

[cekuhnen]

why should it be over constrained? the upper right corner is fixed,
width and height are set on two edges and the distance of the lower left corner is set to the sketch center.

[HughesTooling]

It looks over constrained because you can't move the lower left corner as it is constrained by the dimensions from the origin and you can't move the upper right corner as it's anchored. That means the dimensions for the size are over constraints. Can you change the size of the rectangle. Just to add to the confusion when I try drawing the same I get fully constrained without the anchor!

Mark

[Anonymous]

Claas, I just tried your example, and am repeatedly getting different behavior than you are seeing.  For your most recent example, this is what I'm seeing:

As you can see, I'm getting a "constrained" indication, with no fixed points being used.  And your other example:

Try saving the file, closing it and reopening it, I noticed that seemed to refresh behavior for me.  Also, under help be sure we have the same versions, I have 2.0.1514

Jesse