Our initial idea was to create something that looks completely different (including scale) when viewed from inside and outside, which is impossible to achieve in real world. We first thought about creating a virtual 3D space that one can walk in and out, but it was hard to draw enough lines before they floated away… so we had to scale down our idea, from creating a space that one can walk into, to maybe just a window that one can view from. And we drew what’s shown in these videos.

Do the lines look like a viewport? I doubt… But at least it’s something I can walk around or “look at” as if it’s really there.

To be honest, we don’t think Just A Line is a very effective 3D prototyping tool. But we had fun playing with it though, so despite we don’t know how it works or why it makes the errors, trying out the newest tools is still pretty cool.