3mf file import bug?  

RE: 3mf file import bug?

Hi I've tried to share my files but a lot of my posts are under "Moderating"

RE: 3mf file import bug?

Hi I've tried to share my files but a lot of my posts are under "Moderating"

Files

Hi,

I see now that my posts have been released now.

Please check this one containing the files: Posted : 29/09/2021 11:14 am

BR

Johan

As with Lynn's files yours are also using the CAD origin and so are being placed far behind the plater.  The z is being adjusted down so the part would be on the plater if the x/y coordinates are adjusted.  None of the files are multi-part  though so there's nothing stopping you from placing them on the plater as you would normally.  The arrange issue is annoying I agree though.

Though as mentioned already the PS2.4 alpha software has already been adjusted to place a 3mf like an stl now so the issue is already 'fixed'.  

Be patient

We have issues with spammers doing drive-by dumps. Just keep posting and the mods will release your posts. They're overworked and volunteers, so it can take a little time before they approve your posts. This is a one-time thing.

PS2.4 alpha still has problem with 3mf's

Tried out the PS2.4 Alpha.

I experienced the following problems:

1. If you import several 3mf's in the same project, some bodies still end up on the outside.
2. You are not able to drag and drop more than 1 file at the same time.
3. Rearranging a body on the plate (If there is several bodies) make the rearranged body to drop the old position.
4. Problem reading some files gives several different errors and warnings ( I discouvered this when I added body 19 and 20 of my files.)
   • Warning: An object outside the print area was detected.
   • "No layers were detected. You might want to repair your STL file(s) or check their size or thickness and retry." 
   • Arrangement ignored the following objects which we can't fit into a single bed: body 19.

A question from my side: 

Do you really need to use the world origin?

As I see it you should ignore the world origin and only use the origin of the body.

You have come a long way forward, but you are not finished with this and I will not go for Prusas recommendation to use the 3mf file format until the problems has been resolved.

I would also not recommend anybody else to use this file format unless they have single bodies created out of a cad that has only 1 body inside.

BR

JOhan

Johan, this is a user to user forum (mainly).  Posting issues you have found in the alpha here is the wrong place.  All bug reports need to be made over on the Prusa Slicer github.  Its the only way to make sure they are known about and then eventually fixed.

To address at least one of your points, ALL bodies drop to the plate.  Regardless of type.  You cant (at the moment) position any body that does not have at least part of the body in contact with the plate level.  Multi part objects that are actually grouped can get around this as long as part of 1 of the bodies is in contact.  There is a massive issue over on github about it that has gone on for years https://github.com/prusa3d/PrusaSlicer/issues/1513 .  Its only in 2.4 that they have allowed you to move parts BELOW the bed.  Normally in 2.3 and earlier you would need to perform a cut operation if you only wanted to print something above a certain point.

The software I use for design (Blender) doesn't have a 3mf output as yet so I cant generate any multipart bodies to test with.  I'm curious to see these problems you mention from a personal standpoint but no one has yet has posted a multipart 3mf here we can use to try out and demonstrate the issues.

The other issues with your bodies we cant advise on as you haven't given any details about them.  Do the same bodies when transferred as say stl give the same warnings ?  There are many geometries that when sliced can generate those sorts of issues.  For example something pointed and placed point down on the plater can give the missing layers detected message as the first layer becomes too small to slice with the default elephants foot compensation.

Reply to Neophyl

Hi,

I know this is a user forum, but the PS2.4 was mentioned so I tried it out and I got some unwanted results which I wanted to share.

The files that I provided earlier is generated out of a big CAD drawing with multiple parts and multiple origos.

Generating STL files from these bodies and importing them into PS does not generate the problems I have if I generate 3mf's and importing them.

Also as I understand, (correct me if I'm wrong) you are one of the developers of this function , or you are at least involved in the development of PS.

So I think this is valuable information for you to carry back and it's also valuable information for normal users that do not use github for posting errors and who get information in this post related to a new PS version that as you say yet not been released saying "I don't see these problems in PS version 2.4"

If I can help out somehow to improve the functionality and give additional information to other users we all benefit from this as I see it.

BR

Johan

3mf text editor

Another question,

Is there a 3mf text editor in which you can read the file in clear text?

Also it would be good if you could open and compare it with an STL file of the same model.

BR

Johan

Regarding 3mf files generated out of Fusion

I found an online 3mf reader https://filext.com/file-extension/3MF  

I uploaded one of my files and discovered the file contains only the world coordinates.

So the problem that I'm experiencing is most probably related to how the file is created from the Fusion side.

I will address this problem to Fusion 360 development team.

BR

Johan

No I am not a developer, just an involved interested user.  I am a software tester though in my normal job so these sorts of issues are interesting to me.   Its why I suggested opening issues over on github as anything posted here is not guaranteed to reach Prusa's devs. 

As far as I can see the 3mf file format is actually a form of zip type archive.  If you rename a 3mf file to .zip you can then 'extract' it like any other zip and look at the contents and structure.  The prusa slicer generated 3mf files (Save Project As) contain things like xml and config files for the settings used and other files if you have painted on support areas for example as well as the objects.  The objects/bodies seem to be stored as type .model.  Now those can be opened in something like notepad++ and look to basically be xml in format.  They describe vertices and triangle locations.  How you would plot those out I'm not sure.  There might be a viewer somewhere.  stl files can also be opened in notepad++.  They also basically describe coordinates but the arrangement is different.  

What I have noticed about those vertices locations though is that looking at the object vertices locations for 1.3mf as provided by Lynn that the vertices are <vertex x="911.791488" y="220.768448" z="753.945280" />  which is the coordinates from the CAD origin. 
I don't have an equivalent stl version of that file/model but looking at other stl files the vertices location numbers are more like "vertex 2.396733e+000 -7.787457e-001 1.400000e+002" which to me look they use a more 'local' origin.  

If I had something cad that could generate 3mf as an output then generating a simple cube and outputting it as both 3mf and stl and then repositioning it in cad and repeating would be an interesting exercise.   Although I suspect the stl versions would be identical regardless of where it was in cad while the 3mf version would change.  As you can generate a cube and output it in both formats you could do it and just check.  
What I am more interested in though are the multipart objects.  With multipart stl imports we have the Prusa Slicer options to split to parts (which preserves the relative locations) or split to objects (which doesn't and they will all drop to the bed).  I'd like to see how those options function with a multipart 3mf.