Experimenting with perspective distortion and 2D elements

#1

For a while, I’ve had 2D elements overlayed on top of the 3D world in Might is Right, and it looked pretty good to me.

2020-02-07 07_38_43-Window
2020-02-07 07_38_43-Window1050×731 1.23 MB

But lately I’ve been wondering, what if I could apply rotation of these 2d elements based on camera transform. So I spent a bit of time and added support for that into the engine. Here’s what that looks like:

2020-02-07 07_40_12-Window
2020-02-07 07_40_12-Window1050×731 1.22 MB

Honestly, I’m pretty happy.

Right now I compute rotation by taking 2 points in the world and transforming them both into view space, then taking the delta and using good old Math.atan2.

const angle = Math.atan2(up_ndcY - ndcY, up_ndcX - ndcX);

I keep thinking that there must be a better way to do that, to avoid all that extra math, plus the second point seems a bit wonky, I’m just taking the original world point + Vector(0,1,0).

Anyone got ideas?

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#2

yes, why dont you just take 2D point at a fixed y below the screen, and rotate 2D items towards that? without any 3D voodoo at all? that is, assuming 3D camera does follow your character at the fixed distance

#3

ha, that’s not a bad idea, but the camera is mostly free. Plus I wanted an engine solution, not something specific to a given camera setup. Though it is a bit hacky right now.

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