Scaling Skanect exports with color

[Fred Kahl]

Hi all-

I've been scanning and 3d printing on desktop 3D printers for ages and have no issues with the workflow of going from scan to print without the color data, but am still a relative newbie when it comes to scanning and printing in color. I'm used to scanning, doing some file cleanup in Netfabb Basic, then Zbrush if necessary before outputting as STL for print. While Skanect offers the ability to export directly to Sculpteo and Shapeways, it doesn't allow me to manipulate and edit the scan, or hollow it out to cut down on the print cost. Shapeways export also only allows for sizing in generic amounts such as 2.5%,5%, 10%, 20%. What if I want it a particular height? 

Can someone help answer a few questions about exporting from Skanect to print in full color?

What format is best to save in? It would be easiest for me to work with PLY with per vertex color, but it seems that at least Shapeways does not take this? I'm a little lost in figuring out the workflow of exporting UV testures and saving to a VRML97 or X3D file as indicated here: https://www.shapeways.com/tutorials/exporting_to_vrml_and_x3d_for_color_printing

Any tips on scaling after exported from Skanect and edited? I usually do this in Netfabb, but the color data gets stripped. How do I scale the exported color scan? This seems like a much needed feature in Skanect! 

If anyone can help shed light on this, it would be greatly appreciated! 

Fred

[We3DU]

Hey Fred,

I've watched a lot of your videos and I'm in awe of you, man. In fact I might say you inspired me to get into 3D scanning with the Kinect way back...erm...a year ago! Great to see ya here!

I usually export my ItSeez3D scans in OBJ format and then pick them up with Meshlab, if that's any help, but I'm in the same position as you are as regards Skanect scans. Far as I can make out, you need Blender, Rhino or something similar to preserve the texture while you modify the mesh. I've found that Meshmixer is useful for hollowing but only for non-textured meshes.

Will be watching this thread with interest!

Cheers!

AndyL

Pot8oSh3D

[Fred Kahl]

In researching today and playing around with Zbrush (My editor of choice), I found a PLY importer. I can import a PLY with color, dynamesh, clean surface texture(or hollow out), touch up paint, then use the built in 3D print exporter to scale and export a PLY or .WRL with color. This seems to be the best approach as far as I have found today. 

Fred

[TechLite]

Fred,
If all you need is scaling, then Meshlab works great. I typically save all 3 formats - .obj with textures, vrml and ply with per vertex color. I always save using formats with textures plus at least one with per vertex.  When I save .ply files from Skanect though, Meshlab does not see the color data. If I need to fix minor issues with the mesh, I use Blender. Blender also scales models easily and also works great for improving the poor textures from Skanect. If I need to hollow out or smooth, I use Meshmixer, but as you point out, it strips color. Finally, I use Blender to save vrml2 with UV textures and zip it for Shapeways. I always open my final mesh in Meshlab and if it shows up properly, then I feel satisfied that Shapeways will take it. I've had hit or miss luck using VRML files with per vertex colors only at Shapeways.

So typical flow is Skanect -> meshmixer to hollow -> stl no color -> import to blender and create new UV texture using one of the original OBJ with textures to bake back into the stl. Scale and save to VRML. Check with Meshlab.
-OR-
ItSeez3D OBJ -> Meshlab. Scale. Export VRML with per vertex colors to shapeways.

All that said, the 3D "standard" formats are apparently different among the various vendors so I save the original output files.
I use ItSeez3D if I want the best textures and mail both OBJ and PLY files to myself to save them. When scanning with Skanect, I make a second scan of the person using only the iPad camera hi res snapshots then use Blender to overlay onto the texture for critical areas like the face and notable details. 

It would be great if Skanect put out better textures but the 640 x 480 color.jpg files are terrible to begin with. The new colorizer in 1.8 does slightly improve the texture, but no where near what the iPad camera can deliver as demonstrated by ItSeez3D.

Hope this helps.

On Monday, February 9, 2015 at 7:30:16 PM UTC-5, Fred Kahl wrote:

[skiller1234]

Agreed with the others.  For me Itseez3D produces better results consistently then skanect...

  

After I have a scan I email them to me and open first in meshlap to scale it (usually my factor is about 100 - which gives me a 4-5 inch tall full figure).  Resave as _scaled.

Then into Meshmixer to hollow and make exit holes, its just super easy there... - ... If you save as OBJ format w/ vertex color you don't lose the texture although I think it changes the name of the texture file being used (ends in _materials?) Save again as _scaled_hollow.

You can test it for color and verify holes by opening it again in Meshlab.  ...

For Shapeways i have to then re-export it as a .x3d file, Then zip up the x3d, and the newest texture file (now ending in materials_0) and send it in.  

For Scupteo I stick with the OBJ,MTL and texture files from MeshMixer, zip those up...

This is very basic - but it works for my hollow cost efficient models.  

I have yet to master the art of meshing with the mesh/texture to improve quality.  I have watched James and his Crowtree studios tutorials (which I highly recommend), but always get screwed up in blender.  If anyone can offer some tips on improving the texture in blender or a another nice video of it that would be great.   

One thing - in Meshlab you can turn the lighting on and off with the lightbulb on the toolbar.  That alone can make it look a ton better - but i can't get that simple change to stick and be permanent.  Does anyone know how to do that??

skiller

[Fred Kahl]

I'm just looking at the fastest possible workflow to go from scan to scaled print. The fewer steps the better. 

Can anyone point me to any tutorials for hollowing? 

thx

[TechLite]

Hi Fred.
We're all looking for that. And it's one of the reasons I'm hoping for much better textures from Skanect. Itseez3D is still far better and subsequently has faster workflow.

For hollowing, check out https://www.youtube.com/watch?v=S9sHY7aH--0 a tut done by James at Crowtreesstudios,com. It works great, but will likely destroy color and you'll have to save as STL then bake colors back on to it. (another 3-part tut from James. Just search for crowtreesstudios.) It works well, but is time consuming.

I have used Meshmixer to hollow out models, but you have to pay attention to sizes. Meshmixer is kinda weird if using it with Blender afterwards. In terms of saving time, it's not clear that using Meshmixer to hollow out then bake colors back is the best/fastest method. I've used Blender to make a uniform cutout on the bottom of busts using Boolean modifier with a standard "armature" that I made. The armature also has my logo on it so I can stamp and semi hollow all the busts that I make rather quickly.

Unfortunately, there is no sense to hollowing out a standing figure unless it is gigantic :-D

[We3DU]

That's a great video. James is a real master, but the newer versions of Meshmixer make hollowing and exit holes even easier. Just import your model, hit Edit, Hollow, chose your options and you're good to go. Or at least good to texture.

Cheers!

AndyL

[Jeremy Barker]

Tutorial on hollowing in Meshmixer 

[Tobby Ryan]

Tip to put back the texture if it is stripped...and you already use Meshlab.....

load original model (either the ply or obj+texture) 

Click Filters/Texture/Texture to Vertex Colors (between 2 meshes) .

Select original as source, hollow as destination

in right, highlight and remove the original mesh

Save as preferred format.  (if you need the new texture, you may select "Filters/Texture/Vertex Color to Texture" to export it before saving the obj.)

This method also works if you change the UVMap of an obj/etc and wish to re-project the textures onto it, so its easier to have a simpler texture map for editing.

I use it to do a front/back re-uvmap of a person, then all I have to do to edit/change is paint in any picture editing program by painting on the front/back and reload it.

[ziv schneider]

Hi Fred,

I am a newbie on this forum and found this thread. I am desperately seeking a PLY importer.
Do you have a link to what you've found?
That would be super helpful. Thanks!

Ziv

[Fred Kahl]

Here is a ZBrush PLY Importer:

http://www.zbrushcentral.com/showthread.php?193288-PLY-format-plugin-for-ZBrush-4R7