Combine Meshes

The Cost ..
When you have something printed at Shapeways you get charged for the material (cm3), the shipping (in the US is a flat-rate $6.50) and a ‘handling charge’ that varies. For FUD it is $5. The problem is that suppose you upload a widget. You a proud of it and want it printed in FUD. You find that the cost of the material is only 10¢ .. but the shipping is $6.50 and the handling charge is $5.00

Ok. You figure .. one will cost me $11.60 .. but if I order ten of them then the total cost would be $12.50 and the by-piece cost would drop to $1.25 each .. and you drop the order .. and you are charged a total of $57.50!! What happened?

Shapeways had charged .. 10 ea at 10¢ = $1 .. + $6.50 shipping … PLUS .. $5 handling X 10 = $50

The answer would be then to combine ten copies of the widget into one mesh. That way you would only be charged that $5 handling fee once. If you really wanted to drop the cost then have a hundred printed. You would then be charged 100 x 10¢ or $10 for material cost. You would pay $6.50 and a $5.00 handling fee .. for a total of $21.50 .. and your cost per piece would drop to 21-1/2¢ each.

A single mesh
widget (Bridge Shoe Ver 4)

widget (Bridge Shoe Ver 4)

I am going to use as an example a bridge shoe I designed recently. It was designed for WSF and not FUD but that matters only in the minimum wall thickness of the object.

I have named it .. widget

I am making the assumption that you have a .stl file ready

If you don’t have MeshLab, you can download it for free.

In the following steps you can click the image for a larger version.

Import Mesh Dialog
import_meshWhen you open MeshLab you get a big purple screen. The circle with a cross-hair is where your mesh loads. You move around zoom and out using the scroll wheel .. and by grabbing the circle with the left mouse button you can spin any direction and you can pan the object by holding down the scroll button and moving the mouse. First: Select File –> Import Mesh
Select your .dae file
import_widgetLocate your mesh. MeshLab will import just about anything. In this case I imported my widget.dae file that I exported from Sketchup. If you already have a .stl file then import that. In fact .. one of the steps is that I run the .stl file through netFabb to correct errors and export a corrected .stl (although lately I have been getting better at getting a .stl file from MeshLab that is without errors even before netFabb)
.. or your .stl file
import_widgetThe screen is the same if .. as here .. you wanted to lad a .stl file. Locate your .stl file, select it and click ‘Open’. In this case I am going to import my widget.stl
Post-Open Processing
post_openingWhen I get this screen I just click ‘OK‘. Clicking the ‘Info’ basically tells me .. click ‘OK‘. Go figure.
Show Layer Dialog
show_layer_dialogWhen your mesh loads it does so in the center of the screen. Use the scroll button to zoom in or out until you are happy. First thing .. look up on the menu bar. In the example just below ‘Windows’ you see what looks like a stack of sheets of paper. That is the ‘Show Layer Dialog” button. In fact .. it says just that as I hovered over it for the screen capture.

Select it.

Layer dialog Screen
show_layer_dialog2.. and here we are. There is only one layer as I only imported the one mesh .. my widget.dae in this case. If I had loaded a widget.stl then you would see that.
Duplicate Layer
duplicate_layerNow we can duplicate the current layer. When I say ‘current layer’ it means which ever one is highlighted.

Right click on the layer that you want to work on. From the context menu select ‘Duplicate Current Layer‘.

Note there are various options – the ones I use are:

  • Delete Current Mesh – This deletes the layer you have highlighted. I have done this when I created a layer by mistake.
  • Flatten Visible Layers – just what it says. Note the eye to the left of the layer name. By clicking the eye you can turn that layer visible or not. You can use this to merge specif layers for example.
  • Freeze Current Matrix – this applies whatever filters you have used. I always use this before saving the finished file .. just to be sure

The rest I haven’t used. The Rename Current Mesh for example is only useful if you saved your work ‘in-progress’ as a MeshLab file.

Warning: There’s no un-do for this stuff .. ask me how I know that.

Two Layers
two_layersWe now have two layers titled widged.dae (original) and widget.dae_copy

You can only see one .. as they occupy the same space. You can hide one by clicking the eye but that helps not at all when it is a copy. Duh.

Move the mesh/layer
transfornNow, let’s move one of the widgets. I’ll move the copy .. you could move the other one. Up to you. From the menu select .. Filters –> Normals, Curvatures and Orientation –> Transform: Move, Translate, Center
Transform along Y Axis
tmc_yaxisThe direction you move the mesh is up to you. Here you see the Transform: Move, Translate, Center screen. Make sure you check the Preview at the bottom left. That gives you a real-time view of what is happening. In this case I entered 15 in the Y Axis box. If you put a negative number in it will move the other direction. I can’t seem to get my stoopid computer to do that .. put in the negative sign so I just move the slider to get a negative number and overwrite with what I want. You HAVE TO APPLY .. or it won’t stay.
Flatten Layers
flattenIt’s up to you if you want to continue adding layers. You can continue duplicating, moving in any way that makes you happy.

Here I am going to flatten these two layers into one. Right click any of the layers and select Flatten Visible Layers from the context menu. Again .. note that you can hide layers by clicking the eye which allows you to flatten .. or combine the meshes you wish into one.

Flatten Dialog Box
flatten_dialogHere you can choose just how you wish to proceed with flattening the layers .. I keep it just like this and am a happy camper.
The Two Merged
mergedMeshLab does it’s thing and you now have one mesh called . MergedMesh (duh). Note box on the bottom .. tells you exactly what it did in exhaustive detail.
Duped this Mesh
duped_xaxisNow we just repeat the process – duplicate the mesh and then transform along the X axis and finally merge them all. What fun.
duped_xaxis_2Just for fun I rotated everything so you can get a good view of where we are at this time .. starting with the one widget we now have four of them arranged 2×2. You would of course have many more then this .. 10×10 or more depending on the size of the model. Remember that for FUD, the maximum bounding box (that’s the area the printer can print) is 127mm x 178mm x 152mm. That’s about 5″ x 7″ x 6″ – so it is plenty of room. You will run out of money before running out of room when printing in FUD.
Dupe on the Z Axis
duped_zaxisHere I’ve duplicated the 4 piece mesh and moved the copy vertically on the Z Axis. I also wanted to show a little 3D of what the stack is looking like. Again .. stack as high as you wish with limits of the bounding box, your model size and your wallet.
Final Merge
all_mergedLike we did before .. merge to one mesh. That’s about it. I could if I wished .. copy THIS mesh as a new layer and move it .. and so on and so on.
Freeze that sucker
freeze_matrixIt says that Freezing the matrix will “Freeze the current transformation matrix into the coords of the vertices of the mesh .. ” .. ok. Whatever. Just freeze the sucker.
Export Mesh
export_mesh_asFrom the menu select: File –> Export Mesh As…

If you select Export Mesh just above it will export as a whatever kind of mesh you have loaded. If it was a .stl file then fine. If it was a .dae then you need to Export Mesh As…

Save that sucker
save_stlFinally. Make sure you select .stl from the drop-down menu. It defaults to a .ply (Stanford Polygon File Format) if you are not paying attention. If that’s what you want then fine. Me . prefer .stl

It will put it in the same folder you loaded the mesh from. This works for me. I suggest you keep all the files from each model in it’s own separate folder .. including the Sketchup .skp files.

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