Also for the "Aperture ABC" project organized by  codytehfox. I was going for a blueprint-like background, with the character and cube looking like cutouts pasted on top of it and maybe some mathematical chalk scribbles.

One of the things I find rather annoying about Portal is how you can apparently pick things up with your hands before you get the portal gun, but once you get it, you can only pick things up using the gun's tractor beam levitation thingie. So you can't actually hang onto a thing while you fire a portal. Because apparently something's happened to your hands and you can't use them for holding things anymore. I mean, sure, one hand's holding the portal gun, but you can't even hold onto a can or a radio and fire the gun without dropping it.

Technically the *magnitude* of your momentum is preserved between portals, but the *direction* is not in general preserved. And actually since it doesn't seem to change mass, we might as well just make it simple and say that portals preserve your *speed* (and thus your kinetic energy) but not in general your *velocity*. Physics geek bunny is geeky.

(I drew this in Paint Tool SAI, spending looooots of time on that Companion Cube and the background with vector layers. The text I added in GIMP.)

Art ©  liljennie
Chell and the Weighted Companion Cube created by Valve.