In BuildingShapeUtils.js the edgeDirection seems to have an error: Pi/2

[DerKarlos]

Your Comment:

• Calculate the angle of each of a shape's edge.
• the angle will be PI > x >= -PI

Your code:

   if (angle >= Math.PI / 2) {
        angle -= Math.PI;
   } else if (angle < -Math.PI / 2) {
        angle += Math.PI;

360 Degrees are two Pi. So it should be:

   if (angle >= Math.PI) {
        angle -= Math.PI * 2;
   } else if (angle < -Math.PI ) {
        angle += Math.PI * 2;

I used your code with https://www.openstreetmap.org/way/24771505
(while ignoring the "direction=S") There are two symmetrical skillions
and one sloped in the wrong direction until I changed your code.

By the way: Are you still interested in this project?
I consider to transcode it to Rust and extend it.
Would you like to contact me? @karlos@mindly.social
This is my actual 3D solution (with TreeJS)

[Beakerboy]

Thanks! Yes I’m still interested in this project, but I just don’t have as much free time as I used to, to mess with it. I created this as a way to fulfill a need I had (prototype and visualize works in progress). I’d be happy to use a more feature rich and better supported alternative if one existed.

[DerKarlos]

Ok, I will tell you, if I start coding my alternative.

I could use your code in my OSMgo.org after some adoptions. You may use it by www.osmgo.org/v03.html and find my version of your code there (WedgeGeometry.js and parts of render_building.js
I may have found more errors:

• In buildingpart.js in the part for “gabled” you call center with the angle. But you can’t rotate because there are no center values yet.

After it seems to work, all roofs were mirrored:

• In Threejs-Geometries WedgeGeometry.js move, I had to invert the calculation for pointY

Now I was happy, but not for long. Some times “splitShape” returns not all needed sides. You may test it here:
https://osmgo.org/v03.html?km=1&lat=49.58298499&lon=11.01612998&ele=40.02&dir=4&view=-31
If I use your IO, both buildings are really puzzled:
https://beakerboy.github.io/OSMBuilding/index.html?id=31361386
bad: https://www.openstreetmap.org/way/31361386
ok!: https://www.openstreetmap.org/way/31361389

I will try to find a function splitShape from OSMBuildings or streets.gl - And there alternative codes:

• https://alexbol99.github.io/flatten-js/Polygon.html#splitToIslands
• https://github.com/bjornharrtell/jsts <== https://gis.stackexchange.com/questions/216977/how-to-split-the-polygon-operation-using-of-jsts