I made this years ago and am just now sharing it. Sorry for the wait you never knew you were waiting for.
There’s two different ways to do isometric projection when using a computer screen:
True, exactly like isometric grid paper and the angles are 30° from horizontal as shown on the Wiki
Super easy to do in blender, just use the provided angles.
which gives you this:
…and digital, which for the benefit of smooth lines and consistent video game sprites uses a slightly off angle.
When zoomed in we see a pattern with lines using two pixels over and one pixel row up. You can do the trig yourself, but this is not perfectly 30°. It is, however, much easier to make by hand (as old games often were) and easier to calculate grid position (and thus, the imaginary 3D space the sprites occupy in “depth”).
A bit harder to do in Blender. I wish I could say I slaved over a hot calculator and furious pumped through calculations but honestly? I just played until it worked.
Some things to note:
Orthographic camera. As opposed to a perspective camera, orthographic means all of your lines are parallel. Since our isometric grid is an orthographic grid, we’ll be needing this. It’s in the camera settings of Blender.
Now, since we want that fixed viewpoint angle, we can’t rotate the camera or move it to look at things. We can, however, use the Shift X and Y to look around our scene and scale to zoom in and out. The physical camera should never change once we’ve set it’s proper location.
Setting up the 3D space. We’ll need two things, one or both you probably already have: a camera and a cube (or empty).
The cube can sit at 0,0,0 (X,Y,Z) and the camera should be moved to (pressing N and inputting the numbers at the top right) 12.05713, -12.05713, 9.84465 (X,Y,Z). Go ahead and lock those numbers if you’d like, to avoid accidentally moving something in the future. Now, the important part. Add a Track To constraint to the camera and target the cube. Play with those axis until it’s back to right side up (for me, -Z and world up is Y).
Pressing 0 on the numpad to see the camera’s view, you should be seeing your cube in isometric. F12 to render. Good? Good. If you want that old school Habbo / Roller Coaster Tycoon look, turn off AA in the render panel and make your resolution 640 x 480. You should notice your render is following that 2×1 line pattern we described above.
Of course, this works just as well with an empty, if you don’t want to see the cube in the render (for building scenes around it, etc.)
Fun fact, this is how to make a geometrically perfect Acrylo logo: Make cube. Join all four top verts into central point, making a pyramid. Move point up two units, so whole thing is four tall and the base 2×2. Smile and clap in delight.
If the instructions aren’t working out for you, or you’re a lazy bum you can download the .blend file here