Bounding box

Can anyone tell me how to get a bounding box in WF2 that is the same
size as the part or assembly?
The one that I get is not a what I was expecting.
I am using INFO, MODEL SIZE and choose either a part or assembly. It
shows a box that is bigger than the object and only has one dimension,
the diagonal.
Maybe I should be setting some value.
What I expected is a box that fits the model exactly, with dimensions
along the three axis.
Does it not do this?
Reply to
Peter
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What you describe is what bounding box does. What are you wanting to do with this bounding box? There may be other functionality you could use.
Reply to
John Wade
/* What you describe is what bounding box does. What are you wanting to do with this bounding box? There may be other functionality you could use. */
I suspect the problem might be the influence of features (datum pts, sketchs, etc.) outside the solid body. I haven't ever tried but creating a Solid Surf copy in an Empty part should take care of that.
As far as getting X, Y, Z dims aligned with box edges ... ? I don't know. I ~think~ that'll have to be done manually created geometry?
Reply to
Jeff Howard
I was hoping for a box that was to the XYZ limits of the model or assembly. One use would be as a shipping container size. I have a friend that uses TRANSMAGIC, which is a CAD translation program. It does a perfect bounding box on the Proe models and surrounds the model with semi transparent walls. They are an exact fit in all 3 directions, plus the length of each side is shown along the sides. I was hoping that Proe does the same thing with the appropriate setting. Also when doing mass properties with TRANSMAGIC, as well as giving the dimensions of the center of mass, there is the option to show XYZ planes at the Center of Mass. These are also shown as semi transparent surfaces, making it much easier to locate the center. I don't suppose that Proe has a setting for that, does it? Peter.
Reply to
Peter
Here's a little something I just discovered. The "bounding box" traces, in all views, pretty much the outline of the default datums for a part and the diagonal cuts through the csys. In this ancient, crude and undeveloped functionality, when the part grows (including when it grows asymmetrically, the datums grow with the features, but they grow SYMMETRICALLY to some distance outside the furthest limit of the part and still passing through the csys.
Do this little experiment to see, graphically and in the extreme, what I'm talking about. Start a part in the usual manner. Make some simple geometry (circle, rectangle) OFFSET from the default datums by about the width of the feature. Now, do 'Info>Model Size' on the resulting solid. The "bounding" box will encompass offset datums, csys and the furthest limit of the part. In other words, it will make a box of the default datums (three sides) and the part (three other sides).
This functionality pretends to measure the size of your part but it just measures the size of the datums extended the length of your part, the diagonal passing from or through the csys. Don't know really what good it is to know the diagonal since there are an infinite number of boxes that could make the same one. Seems like more an artifact of the early ooh-ahh factor of modelling. So, while it might not be much, the claim constantly held: "you can't do THIS in 2D". And Pro/e\PTC have lived on their minimal investment in the functionality, profitably, for 15-20 years.
Reply to
David Janes
Wonder if it's associated with trying to calc approx absolute tolerance values from relative tolerances? That's the only application that comes to mind ...
If I might wander off on a tangent: Is there a way to define model size and extents in a way that will affect zoom scale (refit) and drawing view boundaries; i.e. if solid or surf geometry is offset from model origin or there's a datum point hanging way out in space? [ I know I can define model mode saved views, define partial views, etc. but something like the old acad "zoom visible" command would be nice. I'd be tickled if I found out I've missed something. `;^) ]
Reply to
Jeff Howard
Thanks for the reply. It certainly looks like a very useful function. Just out of interest, I did a Mass properties in WF2 and the center of gravity reported by Proe was different in all 3 axes from the report given in Transmagic. One of the axis was over 1 inch different. The other two were closer. Not sure which one to trust. Peter
Reply to
Peter
Thanks for the reply. It certainly looks like a very useful function. Just out of interest, I did a Mass properties in WF2 and the center of gravity reported by Proe was different in all 3 axes from the report given in Transmagic. One of the axis was over 1 inch different. The other two were closer. Not sure which one to trust.
Not sure either. When I see differences like this, I look for something that might have confused the program: a very irregularly featured part; lots of NURBS surfaces; shelled parts, including unevenly shelled sections~the more complicated the geometry, the more room for error. Have no idea how Transmagic works, but, since Pro/e's COG/COM is used for model and assembly mass properties and for Mechanica analyses, you'd think that, if it were horribly error-prone, someone would have said something by now. Don't remember hearing this mentioned before. Has anyone checked with an acutal manufactured part?
Hmm, seems that Transmagic doesn't seem to feel the need to translate Pro/e parts with the aid of PTC's Granite® interoperability kernel (the cousin of Parasolid & ACIS which they do support). Wonder how they're doing it. Don't wonder they're getting strange results.
Reply to
David Janes

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