"Delete Me"

Will someone please explain the function or the reason why someone
would send a Solidworks file to someone with the words "Delete Me", as
the last entry in the design tree, next to the Extrude Boss Base,
Icon? In the graphics window, is a simple wireframe drawing, seemingly
unrelated to the actual file.
I am positive that there is a valid and sound reason for doing it, I
would appreciate knowing what that reasoning is.
Erika

 

If a complex model is encapsulated with a simple solid such as a
cylinder or cube and then saved, the resulting file is usually much
smaller. If the model is also saved as a wireframe, this also helps
create a smaller file. The purpose is to prepare the file for e-mailing
or archiving to save media space.

The extra feature is the last one in the tree and must be either deleted
or supressed in order to see the model.
Gary

 

I call it "putting the model in a box" for shipment. Check the file
size, then delete the box, shade, save and check the file size again.

 

Why does it make the file smaller?

 

Solidworks has a very complex file format. Part of this format is Parasolid
geometry data, a display list, and the "recipe" or the instructions for
building the part.

The display list and Parasolid data are the two largest parts of the file.
When you extrude a cube over a complex part, these two items are simplified,
resulting in a smaller file. The rest of the part still exists in the form
of instructions. When you delete the cube, SW executes these instructions
and rebuilds the original geometry

All Solidworks really needs are the instructions, and these are very small
(byte wise) in relation to the others.

Mark

 

This is all very interesting! Can someone please explain exactly how
to create the box around the assembly. Is this like going to the
center plane creating a big square and then extruding in both
directions? Has anyone developed a macro for such a task?

Thanks,

Ed

 

The display list and Parasolid data

With some parts the graphics info (render mesh) consumes more memory than either
or, possibly, both combined (a torus might be a good example?). If SW saves
this with the file (faster retrieval) ...

 

Has anyone developed a macro for such a task?

Ecosqueeze does the same thing regarding file size, but without having
the 'delete me' feature. When you extrude the box you are replacing a
complciated display list with six planar faces - ecosqueeze just rips
out the entire thing.
You can strip out whatever you want - the parasolid, the display list
(it can also delete the preview image, but that is usually really small
so I leave it be).

Still free after all these years at Ecocom.com

Ed

(caveat - SWx reserves the right to redo its code at any time, so there
is a chance that using ecosqueeze could really mess something up. SWx
urges us not to use any compression/defrag utilties, However, I've used
it likely thousands of times and never lost a byte of data)

 

Ed,

This method doesn't work on assemblies, only parts. An assembly is nothing
more than a display list with pointers that reference individual part files.

As someone else pointed out, Ecosqueeze will do the same thing on a single
part, a whole directory, or even a whole hard drive. Use at own risk

Mark

 

So would "Delete Body" work the same way? I assume it would.

 

Hey Parel,

Nope! Just tried it and the Delete Body was almost twice as big.
Before someone asks, the one file wasn't exactly twice the size, I opened
and closed the models a few times to make sure that the Windows doubling
thing wasn't affecting my results.

Muggs

 

That is just one of the many ways to make SW files smaller for
transfer. There are others, in no particular order or guarantee of
effectiveness:

- move the part/assembly off the screen and save
- change to HLR wirefreame mode
- decrease image quality settings
- turn off setting to save tesselation data
- decrease the size of the SW window
- just do a save as with a different file name
- enclosing in a rectangular solid is better than a cylindrical solid
because there are fewer triangles to display for the flat surface than
the curved surface
- ecosqueeze or unfrag
- configurations cause massive file size issues, deleting configs and
sending a design table separately to recreate the configs can help huge
configured files.
- working rolled back can also cause immense file sizes because SW is
saving body (parasolid) data for each rollback state. not sure how to
purge this data, maybe the save as trick does it or ecosqueeze

I would only use these methods on parts that are being transfered via
FTP or otherwise across the internet - I wouldn't do anything to remove
previews from files being accessed regularly or archived files. Most of
these techniques remove the preview data from the file, which can be
annoying. Archive drives are cheap - I just got a 300 Gb internal drive
for $90.

One of the new functions in SW07 which hasn't gotten much attention so
far is the fact that it automatically creates a preview which is
independent of the orientation or position the file was last saved in.
That means some of the techniques above won't work for SW07 files. It
seems like it changes to an isometric view, does a zoom to fit, and
captures a preview image.

 

The thing with Delete Body is that it is a history based delete (the
Delete Body feature is actually in the FeatureManager), so the body has
to exist before the feature, and it can't be deleted from the actual
file.