Saturday, June 20, 2015

Blender: You think it'd be easy to add an image to an object

So it's time to continue trying to create a game piece in Blender that I can send to a 3D printer.

I've just created a small disc. My next objectives are to give it a little bit of an indent or rim and to try and put an image on top of it.

But first, thanks to everyone for their help and advice in the previous posts. Here's what you've taught me:
  • Check out YouTube and the Blender Foundation for tutorial. The Foundation has a great series on making models that will work for printing
  • When 3D printing, you need a manifold or "watertight" mesh. When you've TABbed into an object and can select its vertices (Edit Mode), make sure you have no vertices selected (hit A, then A again just to be sure. That'll select all, then deselect all). Then choose Select -> Non-Manifold. Blender will tell you if you have illegal geometry (for printing).
  • You'll need to apply the modifiers when you export for 3D printing, but the Export option has a checkbox called "Apply Modifiers", so you can just have Blender do that for you.
  • There are Blender cheat-sheets, including this one: Blender Hotkeys (.pdf)

  • There's a official add-on for 3D printing, that's shipped with the Linux version (which is what I'm using). I need to check User Preferences > Add-ons to confirm it's installed.
    G is the "move selection" hotkey. R is rotate, and S is scale. Holding down Ctrl will let you snap to unit increments as you go (by default - this can be changed).
    The numpad controls your views. You can split your viewport into 4 quarters so you have top, 3D perspective, front, and right views. Like this:
Thanks, +Richie Cyngler, +Adam Schwaninger+Markus Glanzer, +Winchell Chung and +William Black.

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The easiest next step should be finding out if I can import a .jpg file and map it over one side of the disc. Here's the image I want to map:

It took a little bit of mucking around in GIMP to create this on a transparent 60x60mm layer. A quick check in Blender's File > Import menu doesn't reveal any obvious options for images.

But accidentally pressing CTRL-TAB brings up the Brush menu and a whole bunch of other painting related options. Seems like that might become useful, soon.

Anyway, this short tutorial shows me how to import an image:


I'm not sure how to move it into the main window, yet. You can't click and drag it.

Further investigation reveals there's an add-on you can activate called 'Import Images as Planes'. The tutorial in that link looked very promising. However, I seem to have simply imported a grey square.

So now I'm wondering if I'm going about this the wrong way. Could I:
  • import the image directly onto a new cylinder, or
  • add the image as a texture to my existing cylinder?
After button-mashing for a bit, I selected the 'Shading' menu and ticked 'Textured Solid', which creates this:

That's pretty close. Now: can I shift it onto the cylinder? ... I've discovered that right-clicking an object selects it. In the 'Object Tools' menu, I can click on 'Translate' and manually shift the image around.

An astounding comedy of error follows, as I accidentally rotate the bull image and shift it 24 metres away from a 39mm large object. After struggling to find and reposition it, I have this:

For my serenity, I walk away for a couple of hours. When I come back, I find (and follow) this crystal clear tutorial, which does exactly what I want:

Following those instructions, I succeed in putting the texture on the disc. You can see it on the right-hand side, below. It's not centred yet, but I'll take the win:

 And that's where I think I'll leave it, for the moment.

Previous posts:
1. Figuring out how to create a 3D object
2. Learning how to create a disc