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GATOR
02-12-2014, 01:36 PM
I'm a long time Lightwave user (10 years) and have just started using it for 3D printing.

I'm finding that overlaid objects, contrary to their video on 3D printing, do not naturally join. The area of intersection creates a void.

When creating I have to abut objects precisely. I've tried doing a boolean 'join' but it's a pretty flaky tool and doesn't work very well. Even on a simple test with two cubes with a little instersect, it fails.

So, my question is....does anyone have a solution short of re-building a model, to make it work with 3D printing?

I can create a model with this in mind, but it takes a lot more effort.

I don't like the idea of using another program, since I have Lightwave pretty nailed down after all these years.

My printing software takes both .STL and .OBJ files, but the flaw shows up in both. I haven't found a post-processing program that can 'repair' this.

Thoughts?

Ztreem
02-12-2014, 02:08 PM
I think this is more of a problem of the printing software than lightwave. As i understand it some printing softwares can use intersected objects and read it as one others can not and you have to join the model. If booleon doesn't work try to move one of the objects a little and test again otherwise you have to do it manually.

GATOR
02-12-2014, 03:22 PM
Is there a program for creating g-code or .x3g files that is preferred for Lightwave generated files?

spherical
02-12-2014, 07:56 PM
Don't really know of one that will swallow models that overlap, no. Multi-mesh isn't the same as intersecting. STL files need to be one water-tight shape, having one inside and one outside, for the slicer to reliably understand it and create the paths necessary to rebuild the shape.

Greenlaw
02-13-2014, 06:08 AM
Here's what I did for our 'Sparklepus' test: I brought the Modeler geometry into 3D Coat as a voxel object and then had the program remesh it using Autopo. The body was a single object but the mane and tail was originally built using several layered pieces, and 3D Coat remeshed these items as single pieces that 'snapped' onto the body.

Then I brought the model back into Modeler, made a few tweaks and output a watertight .stl.

Here's what it looked like. We used a Form 1 desktop printer and it came out perfectly.

Sparklepus (http://littlegreendog.blogspot.com/2013/07/our-first-3d-print-sparklepus.html)

G.

GATOR
02-13-2014, 08:17 AM
Greenlaw,

That sounds like the kind of solution I need. I downloaded 3D Coat, and seems like a very deep Z-Brush type program. Any chance you can give me a more defined step-by-step on the process you used to remesh the item.
I looked for a YouTube tutorial, but couldn't find one.

Thanks!

GATOR
02-13-2014, 09:36 AM
I think I figured it out. I imported the object using Autopo with a setting of 2500, 2500 0 (it's a mechanical object with lots of detail) and then exported it as an STL file with no reduction. I brought the resulting file into MakerWare for scaling and rotation and then sliced the file with the output going to an SD card (all within MakerWare). The result is in the printer humming along. Looking at the STL file in LW, it looks liked the gaps are gone. The mesh isn't exactly crisp, but the resulting file was a 49mb STL file, so I didn't want to go larger on a first test. Thanks for your feedback Greenlaw, we'll see how this goes.

Greenlaw
02-13-2014, 09:47 AM
Yes, I think that's right: In version 3 you had to first bring your mesh in as a Voxel object and then convert it in the Retopo Room but in version 4 I guess you can do the conversion directly on import. FYI, you can do the same in ZBrush too. I have both but I usually default to 3DC because I'm more familiar with it.

Before printing, check the mesh in your modeling or printing program to be sure it's valid for printing. When I use Autopo, I sometimes find a small patch of missing polygons that need to be filled. It's easy to fix but can be tricky to find. The free MeshLab can be useful for checking geometry.

G.

GATOR
02-13-2014, 10:24 AM
Yes, it seems with the current version you can do it all with just importing, telling it the resolution, and then exporting.

It seems to be printing perfectly and with adequate resolution. One object which had obvious gaps because of the overlaid parts (scaffold of a satellite dish array) held together just like I had wanted.

I did use LW to check the object. I even exported an STL file after checking it...but it came out to be 460 mb in size. Yikes. So on this test I'm just using the export from 3DC with plans to tweak in LW if needed.

Greenlaw
02-13-2014, 10:28 AM
One of the nice features with Autopo is that you can define the polygon flow by drawing lines on the model and specify zones for higher density using a paint brush.

I haven't tried Autopo on import so I'm not sure if these options made an appearance for you--if not, it's worth trying out if you have a complex mesh to print.

G.

spherical
02-13-2014, 03:01 PM
Here's what I did for our 'Sparklepus' test: I brought the Modeler geometry into 3D Coat as a voxel object and then had the program remesh it using Autopo. The body was a single object but the mane and tail was originally built using several layered pieces, and 3D Coat remeshed these items as single pieces that 'snapped' onto the body.

Then I brought the model back into Modeler, made a few tweaks and output a watertight .stl.

Cool. Another reason why making the stretch to get 3DC was a Good Thing. Does import as a voxel make this possible?

Greenlaw
02-13-2014, 03:15 PM
Yes, I've prepped a couple of models for 3D printing this way and it's worked out quite well so far.

As mentioned above, the workflow described above was for 3DC version 3, and version 4 has more options for importing, including import for retopology and import for voxel sculpting. Technically you could do this in 3DC before, but now you can do it directly from the startup screen with far fewer steps.

G.

spherical
02-13-2014, 04:26 PM
Cool, thanks. I'll run a few tests, so I know what to do when I need this. I have a few Borked models that others have posted, saying that the slicer has a bug; when it was crappy modeling. It'll be good to see if they are repaired, as opposed to what I had to go through to do it manually for them.

Ztreem
02-20-2014, 07:48 AM
I've done some tests in makerware and it seems that I was wrong. Intersecting objects is still a problem, seems like an easy thing to fix but it's still the same as in late 90's.
I just come to think about a free software that could be the soulution for your problem... Meshmixer.
And they have also added a function for support srtuctures, look here.
http://www.youtube.com/watch?v=aFTyTV3wwsE&sns=em

zapper1998
02-20-2014, 09:27 AM
I have a Makerbot Replicator 2X if you want me to help check out stuff..

I use mutliple programs and I use Simplify3D alot..

Mike

zapper1998
02-20-2014, 09:51 AM
I am trying our MeshMixer, that looks promising...

and its FREE....

:)

GATOR
02-27-2014, 07:06 PM
Zapper, let me know how it works for you. I'm diving back into this problem after putting it on the shelf while I worked on another project. While 3D Coat gave me a mesh, it was a 65MB mesh and Shapeways choked on it. I was able to print it, and the gaps were gone, but other parts of the print failed.

Fixing the gaps is easy on some parts...but there are places it is REALLY complex. I can't do that for every print. I build models all day long (and have for almost 20 years) and would simply like to print what I build. I have no problem building something from scratch if I know it is heady to the printer. I get that.

The intersection thing is the biggest problem I have.

I bought Simplify 3D, but for some reason the GPX plugin won't run (on both my desktop and my laptop) so it won't output my final file. The folks at Simplify have tried to help, but nothing works...I have the latest OS on my laptop.

So tonight I'm back-tracking and trying the old ReplicatorG. Takes forever compared to Simplify, in terms of slicing. So while it's running I'm back here exploring options. I downloaded MeshMixer, but haven't figured out how it can give me my 'fixed' file. A straight output didn't work on my one test.

Ztreem
03-01-2014, 08:01 AM
You have to save out the object you want to join as separate parts. Then load them in meshmixer and do the intersection in there then export.

zapper1998
03-02-2014, 10:31 AM
~~~
Actually the way to put stuff together is Lightwave Modeler, then make all polys 3 point polys, then export using the STL exporter..

Meshmixer, well been tinkering with the cumbersome thing... I do not like Meshmixer, I like the work flow I have .

Meshmixer it took me an HOUR to figure out how to rotate the bloody object, hahahaha


120545


Load the stl in LW Modeler, modify, repair, export to stl.

Load it up in Simplify3d, and setup in Simplify3d, hit print

And Simplify3d Can handle 100mb files, Makerware can handle 100mb files.

I spent a good day playing with Meshmixer, I don't like it..

I will stick with Simplify3d, its faster and more robust.. and you can modify the gcode, and other things, that Meshmixer can't do..


120546

120547


Mike

Greenlaw
03-02-2014, 11:42 AM
At work, I've been using the new Meta Mesh and Boolean Tool from 3D Powers to create complex forms for spaceships, organic alien structures, etc. These tools can be used for merging multiple objects into a single seamless one, and the results are surprisingly good. I haven't used them for 3D printing yet but the results are almost certainly good enough for that.

Here's their website:

www.3rdPowers.com

And here's the forum thread about it:

Cage and Lattice Deformer, MetaMesh, Boolean, HeatShrink+ Now Available (http://forums.newtek.com/showthread.php?139320-Cage-and-Lattice-Deformer-MetaMesh-Boolean-HeatShrink-Now-Available)

G.

Greenlaw
03-02-2014, 11:48 AM
If you go with the above, here's another handy tool: CM Polydivide (https://www.lightwave3d.com/assets/plugins/entry/cm_polydivide/)

I use this tool (three actually) all the time for closing shapes properly, which you may want to do before merging them with Meta Mesh.

G.