Center Marks of Objects Not Correct

[Bruce Kieffer]

One of the best features of VW 2010 is object center marks. The problem is you can't rely on them. They are not determined correctly for any somewhat complex object, and in the case of the attached screenshots, even a duplicated object has a different center point than its parent. Not good. 1.jpg shows a duplicated and aligned object in right view. 2.jpg is zoomed in on the 2 center points of those "same" objects. I wish I could understand how they are not in the same spot? Same object, one directly on top of the other, residing in the exact same space. I did make tech support aware of this issue, but it has not been corrected in SP3.

[Pat Stanford]

It also appears that there are two circles slightly offset.

I just tried to make an object move on duplicate and could not.

Are you certain the center points are actually from the object and the duplicate? Could there be a third object?

If I were you I would make sure to add (if it is not already there) the Custom Visibility command to your workspace and make a Hide Selected command. Select one of the objects and hide it and see what is left. Repeat until you confirm what object each of the center marks belongs to .

[Bruce Kieffer]

Hi Pat,

The offset circles you refer to are due to 2 solid subtractions from the extruded rectangle. One is a cavity for a hex head nut, the other is a hole. Yes they are a part of the same solid subtraction. I moved the duplicated objects apart in the attached JPG.

I investigated further, and I think the double center marks are in the one solid subtraction object. I attached a VW 2010 file for you to see that. It has the single solid subtraction. Zoom in to see the center marks. VW thinks that object has two different centers. One center for the extrusion with the subtracted hex head cavity, and another center for the extrusion with the subtracted hole. This is what I pointed out to tech support recently with a different example. I will post that example file shortly.

I just added the Custom Visibility command to my workspace. Nice! That's a great topic for my users group. Do you have a link to a tech document or movie that explains more about it?

[Bruce Kieffer]

OK. Attached is another VW file showing in front view an extruded rectangle at the top, and the same extruded rectangle below, this time with a hole cut in it off center. Grab the lower object by the center mark and align it to the upper object's center mark. See what I mean? The center mark of the solid subtraction is not correct. The true center of that is the intersection of the rectangle's width/2 and its height/2. VW calculates is as something else.

[mike m oz]

Bruce if you go into the solid subtraction and look closely you will see that the tube and hexagon objects are not coincident. Their centres are actually 0.004" apart vertically.

It appears that you are using a Workspace from an earlier version. There is always a risk when you do that you will miss out on new features in a new version like you have with the Visibility tool. If you have to customise a workspace it is always better to start with a new version's workspace and modify it. It takes a little longer but you then have a comprehensive up to date workspace.

The Visibility tool is covered in the Creating Drawing Views section of the Vw 2010 Help Vectorworks Design Series manual part.

Edited April 10, 2010 by mike m oz

[Bruce Kieffer]

Bruce if you go into the solid subtraction and look closely you will see that the tube and hexagon objects are not coincident. Their centres are actually 0.004" apart vertically.

Mike,

You are correct, but I ungrouped them, realigned them, subtracted them again, and there are still two center marks on the subtraction.

[Bruce Kieffer]

The Visibility tool is covered in the Creating Drawing Views section of the Vw 2010 Help Vectorworks Design Series manual part.

I think Pat is referring to the custom visibility command, not the visibility tool.

[mike m oz]

Bruce you are right in that Pat was referring to the Custom Visibility command. It works in a similar way to the Visibility tool.

I'd do the Solid Subtraction in a different way. You appear to have done it in two steps. That makes getting the two subtraction parts correctly aligned difficult. Better to align the cylinder and hexagon subtraction parts and then subtract them both from the larger part in one Solid Subtraction. You can have multiple parts in both Solid Subtraction and Solid Addition operations.

[Bruce Kieffer]

I'd do the Solid Subtraction in a different way. You appear to have done it in two steps. That makes getting the two subtraction parts correctly aligned difficult. Better to align the cylinder and hexagon subtraction parts and then subtract them both from the larger part in one Solid Subtraction. You can have multiple parts in both Solid Subtraction and Solid Addition operations.

Mike,

I did do it in one step. I aligned the two objects, then subtract both from the extruded rectangle at the same time. Even so, there are still two center marks.

[mike m oz]

Bruce - your Center Marks 1.vwx file has two separate subtractions in it. When you zoom in close the cylinder and hexagon are not perfectly aligned and therefore the centres of each of the objects are not perfectly aligned.

In the attached file I have undone both solid subtractions, used the Align command to perfectly align the cylinder and the hexagon extrudes and then subtracted them both from the other part in one Solids operation. The centre marks do align.

Edited April 11, 2010 by mike m oz

[Pat Stanford]

Bruce,

I am seeing your problem here. The Center Marks 2 file does show a shift of the center mark when you do the subtraction operation.

Mike, try this to see the real issue:

Draw a rectangle centered at 0,0. Extrude it.

Draw a shape (I tried circles and rectangles) and extrude it.

Do a solid subtraction of the two objects.

The new center mark of the Solid Subtraction will be offset in the X direction. The offset will be in the opposite directions of the location of the subtracted object.

In my opinion it is a bug.

[Pat Stanford]

I just added the Custom Visibility command to my workspace. Nice! That's a great topic for my users group. Do you have a link to a tech document or movie that explains more about it?

I used to use the Custom Visibility quite often when working on 3D models. Since it is no longer a factory part of the workspace I only think to install it when I really need it.

I don't know of any docs or movies to explain it.

I typically used it to create a couple of scripts and then uses those to make it easier to see the part of the model I was working on.

The scripts I usually created where Show All (to get everything back), and Hide Selected. Depending on what I needed I would sometimes add other scripts to hide selected object types or even to Hide Not Selected.

I think the scripts are better than the Visibility Tool in many cases because they can work on the Object level rather than the class or layer level.

[Bruce Kieffer]

Bruce - your Center Marks 1.vwx file has two separate subtractions in it. When you zoom in close the cylinder and hexagon are not perfectly aligned and therefore the centres of each of the objects are not perfectly aligned.

In the attached file I have undone both solid subtractions, used the Align command to perfectly align the cylinder and the hexagon extrudes and then subtracted them both from the other part in one Solids operation. The centre marks do align.

Mike,

I see two center marks on your VW file when I zoom in close.

[mike m oz]

I now see what you are referring to and yes I agree it is incorrect. Apologies for getting the wrong end of the stick.

[Bruce Kieffer]

I now see what you are referring to and yes I agree it is incorrect. Apologies for getting the wrong end of the stick.

No Worries. The object is to get Nemetschek to fix the problem, cause like I said, it's a great tool that unfortunately doesn't work.

[Ray Libby]

Did you file a bug?

[Bruce Kieffer]

Did you file a bug?

I talked with tech support a few weeks ago about this problem, and they said they would make the engineers aware, so I have to say maybe!