What length in pixels does a Wings3D unit of measurement equate to?

[imagine]

If I understand you rightly you've measured the printed block stack.

But I think the final measure in the printing object depends not on wings3d neither the 3d printer but the slicer.

As Oort told me in another thread STL files don't include info about units so it's up to the slicer to interpret the dimensions in the STL, most slicers assume mm so 1 unit in stl is roughly equivalent to 1 mm

Most slicers seem not to have settings to set the units in use or to read from stl files

But my experience is not this. Let me show it with an example:

I make a standard cube 2x2x2 WU in wings 3d 2.2.6.1, the I export it to STL and use Ultimaker cura 4.6 o slic3r to open the STL file, cura automatically scales it x10000% to get a cube of 200x200x200 mm that means real size is 0.02x0.02x0.02 mm; while slic3r reads the STL as a 2x2x2 cube (I'm assuming mm), so 2x2x2 mm and without autoscalling.

The gcode file generated by the slicer has a code for setting units (mm or inches) but is just an indication for 3d printer about how to interpret the units in the gcode file

So it's possible that different slicer software interprets differently the same stl file and thus more than measuring the printed piece should be better applying a filter to import or export procedure.

What I mean is that it would be great to have a dialog in the import STL option of slicer software to set some parameters such as mapping STL units to slicer unit, i.e 1 STL unit = 1 mm AND also to have a dialog in the export option of the modeler (wings 3d in this case) to set a similar set of parameters, i.e. saying 1 STL unit = 10 mm. This will minimize the need for scaling in the software itself.

[micheus]

We know Wings3D is metric independent as well as STL file format doesn't uses any one too.

I think we need to reference the slicer software when talking about to scale the model built with Wings3D.
So, I'm adding an export dialog to the STL format which includes the option to Scale your model before exporting. It also will include a information table with some Slicers references and suggested scale for 1WU=1mm.


There is an user at Instagram @merthancioglu that told me he can try to check for other two slicer tools: 3DWOX Desktop/A Series Desktop from Sindoh and Z-suite from Zortrax

If we get more informations about other slicers I can continue to update the list and maybe - if these information be accurate - we could make the export settings be a little more helpful.

Of course, this change needs to be approved by the main developers.

[imagine]

great news! I think this will make exporting to STL more comfortable. Thanks!

what means subdivision steps? what is it intended for?

[micheus]

That user @merthancioglu already did a check to for other slicers.

The default Wings3D cube 2x2x2WU has these equivalents:

Zortrax Z-Suite: 2x2x2 mm
Up pp3dp ......: 50.8x50.8x50.8 mm
Cura 4.6 ......: 2x2x2 mm
Repetier Host .: 2x2x2 mm
Chitubox ......: 2x2x2 mm
3Dwox Desktop .: 2x2x2 mm

We can see that most of them has the equivalence: 1WU = 1mm
It was a surprise the Up pp3dp.

imagine's post, a cube of 2x2x2WU:
Slic3r: 2x2x2 mm

dawntreader's post, a cube of 5x5x5WU:
MakerBot Print: 5x5x5mm

[oort]

Is "Up pp3dp" assuming the WU are in Inches for some reason and converting them to mm?

(1 Inch = 25.4 Millimeters when converting inches to mm)

2x 25.4 = 50.8

oort

[micheus]

It looks like. Thanks for pointing that, because I didn't realize it before.

[oort]

In the past I have dealt with converting from inches to mm and the value 50.8 caught my eye...

Thanks for making the updates. Hopefully it will bring more people to use Wings3D.

oort

[micheus]

what means subdivision steps? what is it intended for?

It's equivalent to apply smooth to your model just before write the data to the STL file.
It's a common option in the other exporter dialogs - although I'm not sure it would be as so useful for models to be printed.

The current (and I think the final) layout to be proposed to the main devs is this one:


a) left, is equivalent to the current implementation: 1WU represents 1STL unit and the Export scale just represents a multiple of that.
b) right, is related to the meaning we gave to the 1WU when we modelled the object. With that information and the selection of the slicer tool we are going to export to, we get a computed scale that should make the slicer reproduce the object using the dimensions based on the meaning we used for Wings3D scale. (by supposing the slice will not auto-scale the model )

But, supposing that we still want to get our object printed with the double of the size, for instance, we can use that computed scale and multiply it by the desired factor. I put a note about that just below the table.

NOTE: Wings3D plugin automatically rotate the model around X axis to make the Y axis match with the Z axis at the 3D printer. That is why there is no option related to that in the dialog.

If someone want to test it and give me a feedback here is the link to download the patch. Use the option File->Install Plug-in or Patch in the main menu to "replace" the original one.

[micheus]

Forget about the previous post.

As I workaround a small limitation with that table control, I got a better functionality to the dialog - with suggestion of oort: it computes automatically the "Export scale" value if we choose one conversion unit from the dropdown list box and use one of those presets listed on the table; As well as setting the object scale intended.

Here is the new layout (more clean and useful):


Again, if someone want to test it and give me a feedback here is the link to download the patch. Use the option File->Install Plug-in or Patch in the main menu to "replace" the original one.

[oort]

Micheus,

The plugin works great.

I have tested with both Cura and Slic3r software.
I still want to test with Up Studio

imagine,

I found information on why some models are scaled up by Cura. If you export a cube that is 3x3x3 instead of 2x2x2 the model will import without being scaled.

There is a setting in Cura named "Scale Extremely small models" that can be turned off. It is under "Opening and Saving files" in the "General" section of "Preferences" in Cura.

Why is Cura Auto Scaling

With the plugin changes that Micheus has worked on, you could either export as 1WU = 1cm or set the export scale to 2.0

oort