Any way to fix incorrect scale of STL dimensions?

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Galane
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Any way to fix incorrect scale of STL dimensions?

Post by Galane »

tS 6.6 always loads STL files far smaller than the dimensions they should have, and apparently unless all the scene settings are on meters or milimeters, it saves the dimensions inaccurately.

For example I have an STL that opens in Cura at correct size of 42, 12, 11.9 (X Y Z) but in trueSpace it opens as 8, 2.286, 2.267 If I resize it to the correct dimensions and save it as STL, it's shrunk again when re-opening.

Even screwier, after upsizing to proper dimensions and saving to a new STL, that new STL will again load in shrunken. If I save that new STL again to another new file *it does not shrink it again*. It will re-load exactly the same shrunken dimensions as when loading the original.

How the heck can it do that? If it fouls up the scaling it should do it iteratively so that every time its saved as STL it should shrink the dimensions, but it doesn't.

But wait, the bugs are odder yet. It doesn't matter if I'm working in meters or millimeters, the STL output from trueSpace always loads the same size in Cura. trueSpace is apparently incorrectly applying the setting for millimeters to an STL that should be scaled in meters - but it cannot correctly *read* the scale from any STL, be it in metric or imperial units.

How I work around this mess of bugs is load an STL into Cura to get the proper size. Load the STL into trueSpace then enter the real dimensions to scale it up, then save as COB for working on the object. Save as STL when I want to print, and only work in meters or millimeters (haven't tried centimeters or decimeters).

But wait! There's more! I just switched to Inches for all settings and popped in a cube primitive at 2 inches. I saved as STL. Cura loaded it as *two millimeters" instead of 50.8. When I loaded that STL back into trueSpace it came in as EIGHT INCHES.

Is there some way to hack trueSpace so it can both read and write scale information correctly in STL? From the time STL support was first added to trueSpace, it's had these bugs and Caligari never bothered to fix them.

Would be nice if Microsoft would release the source code so other people could finally get to fixing all the problems neither Caligari nor Microsoft ever bothered to.
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Emmanuel
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Re: Any way to fix incorrect scale of STL dimensions?

Post by Emmanuel »

Did you tried to use an external program to convert your .cob files into .stl ?
I've got an old 3D conversion program called 3D Exploration, by RightHemisphere that works pretty well with trueSpace and STL files. My version is a 2001 release ; it's quite old but it does the job.
Galane
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Re: Any way to fix incorrect scale of STL dimensions?

Post by Galane »

Emmanuel wrote:Did you tried to use an external program to convert your .cob files into .stl ?
I've got an old 3D conversion program called 3D Exploration, by RightHemisphere that works pretty well with trueSpace and STL files. My version is a 2001 release ; it's quite old but it does the job.
Got a link for that?

Put the scene settings all to millimeters. Pop in a cube primitive then save it as COB. Use 3D exploration to convert to STL and see if trueSpace imports it the proper size.

If it does, save the cube as STL to a different file name then import that one to see if it gets the scale wrong.
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clintonman
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Re: Any way to fix incorrect scale of STL dimensions?

Post by clintonman »

The units in truespace are crazy.
Be sure that when you import that the settings are not set for "Screen Fit". Truespace is natively meters so I'd stay away from all other units, because of the craziness. I don't believe stl files have units. It's all dependent on the program that's reading/writing it.
Clinton Reese

http://clintons3d.com
Galane
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Re: Any way to fix incorrect scale of STL dimensions?

Post by Galane »

Slicers for 3D printers correctly read the scale and units from STL. After opening a lot of STL files in tS 6.6 I see what it does. It scales the largest dimension to 8 units, with the other two scaled the same percentage.

There should be a way to hack it to fix that. I don't know which file is responsible for reading STL but I'm pretty sure the bugs with setting the scale incorrectly on *export* for everything but millimeters (and using mm settings when you want Meters) are in StlExport.dll Is that file also used for importing?
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BNG
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Re: Any way to fix incorrect scale of STL dimensions?

Post by BNG »

Galane wrote:
Emmanuel wrote:Did you tried to use an external program to convert your .cob files into .stl ?
I've got an old 3D conversion program called 3D Exploration, by RightHemisphere that works pretty well with trueSpace and STL files. My version is a 2001 release ; it's quite old but it does the job.
Got a link for that?

Put the scene settings all to millimeters. Pop in a cube primitive then save it as COB. Use 3D exploration to convert to STL and see if trueSpace imports it the proper size.

If it does, save the cube as STL to a different file name then import that one to see if it gets the scale wrong.
Here's a link for 3d Exploration I use 3DEX all the time and it work very well. Leroy.
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