What changed
- Before: the spot was a circle on the texture, squashed a little across the body and with ragged edges like any other patch. The texture is stretched over a head that is much narrower than it is long, so on the koi the spot came out as a small oval, about 0.3 body widths across and 0.5 long.
- After: the spot is measured where it is seen. Each point is moved into the koi's real proportions (length from the body's genes, width from the same outline the mesh uses) before measuring the distance to the centre, so it is a true circle on the fish. It has a soft edge but no ragged one. Its size is worked out from the eyes: as big as it can be while leaving a small white gap to the nearer eye, capped at two thirds of the head's width. The result is 0.36 to 0.5 body widths across, depending on the koi's shape.
Why
The r/Koi judge: a Tancho's spot should be bigger and perfectly round, as large as possible without touching the eyes. On a Tancho the spot is the whole fish, so judges look closely at its shape. A clean circle is worth more than any extra colour.
