I think that this trick or something like it is used in ski mountain maps. For example: https://files.skimap.org/js03b74i9eokcg2y1iakwdtv2av6.pdf https://files.

I think that this trick or something like it is used in ski mountain maps. For example: https://files.skimap.org/js03b74i9eokcg2y1iakwdtv2av6.pdf https://files.skimap.org/js03b74i9eokcg2y1iakwdtv2av6.pdf I don't know how to confirm this; the distortion just feels similar to me.