Sketch Basics: Explain Extra Sketch Point

[tookemtoni]

Hi, I know how important it is to have fully defined sketches. And that starts with understanding the geometry you’re constraining to.

I get a bit overwhelmed when a slow left click reveals so many sketch points and try to figure out which one to select.

See Screenshot.

Could someone explain what does extra point is for?

See Video Demo and F3D

[Warmingup1953]

I think it is there because you are in 3D sketch mode but I'll check now Im at the PC

[aliobidi · Accepted solution]

Hi , 

this sketch point at the origin define the sketch location this useful in API   
it appear even if you draw a point and can't delete it  

[Warmingup1953]

I see its there both in 2D and 3D sketch made as soon as you get going so to speak...I think its there because it needs to be?

[tookemtoni]

OK that makes sense

[tookemtoni]

Thank you for the replies. Here is another video demo. Only in 2D sketches.  Still 6 sketch points.  This really is not a problem.  I will just treat it as normal and carefully select the points in the future.

[HughesTooling]

One problem is when you constrain to the origin you select the document origin not the sketch origin. This will project the document origin into the sketch so you get 3 point in the first sketch rather than 2 if you use the sketch origin point. Hard to know why you get 3 more points from the second sketch without see you create it. Can you export the file as an f3d before you constrain the first sketch to the origin and attach it here? Actually I think the second sketch has one projected point from the first sketch, one end point from the line and it will also have an origin sketch point. So six point is correct for what you've done. You would get one less is you hide the document origin and just use the sketch origin.

[HughesTooling · Accepted solution]

Here's a screencast showing the points in each sketch. Easier to see is you hide the document origin and hide one sketch while looking at the points.

Mark

[tookemtoni]

Thanks @HughesTooling

Hiding sketches that you don't want involved in the constraining operation is a good idea. But do you confirm that there is this extra point at the origin that is included with each sketch geometry?

[HughesTooling]

Every sketch has a point at its origin but it only becomes permanently visible when you attach something to it.

Here is a new sketch and when you mouse over its origin and click it shows in the selection menu.

After starting a line from the origin the point then shows as a projected point.

Now if you click and hold it shows 2 points, the origin and the line end point.