The number in the title is not random. It is equal to arcsin(tan(30 deg)) which is the exact angle to preserve aspect ratio in an isomorphic projection. I have created a custom perspective and used values such as 35, 35.3, 35.264, and the one in the title, but it always comes out with jagged lines like the following:

Notice that the edges of the blocks are not very straight/linear. They jump around a lot.

Here is what we are looking at from the top:

I thought it could be a scaling issue so I rendered it at scale 16 instead of 4:

It looks great zoomed out, but up close the problem persists:

I know, I'm being picky, but I am curious why it's not perfect and if there is a solution to make it so. If not, oh well I guess. 16 looks great but I can only render the whole map at 4 on my hardware due to disk size constraints. It would be amazing to have it at a perfect aspect ratio without the jaggies.

Thanks for any help. Here are my perspectives:

  - class: org.dynmap.hdmap.IsoHDPerspective 
    name: iso_SE_35_vlowres
    azimuth: 135
    inclination: 35.2643896828
    scale: 2

  - class: org.dynmap.hdmap.IsoHDPerspective 
    name: iso_SE_35_lowres
    azimuth: 135
    inclination: 35.2643896828
    scale: 4

  - class: org.dynmap.hdmap.IsoHDPerspective 
    name: iso_SE_35_medres
    azimuth: 135
    inclination: 35.2643896828
    scale: 8
    
  - class: org.dynmap.hdmap.IsoHDPerspective 
    name: iso_SE_35_hires
    azimuth: 135
    inclination: 35.2643896828
    scale: 16

Avoiding that would require anti-aliasing via super-sampling and blending pixels, which would increase render time by 2x or 4x. Not going to happen. Dial up your resolution - that'll give you the equivalent results, and switch to JPEG format if you'd prefer softer edges.