Every map in a surveyor’s office hangs on one point: the datum, a fixed marker whose coordinates are agreed once and never renegotiated. Every measurement after that is fast and trustworthy precisely because the first point does not move. AI series fail for the opposite reason — the character is re-described from memory in every prompt, and memory edits. One session she has “long dark-brown hair,” the next “brunette waves,” and the audience watches a stranger take over the page.
What a datum is made of
A working character datum has five anchors, in this order: age (always 25 or over, stated as a number), hair (colour, length, one default style), build (two or three words, no more), face (one or two durable details — a calm expression, a strong brow, green eyes), and a signature (the pendant, the ring, the beauty mark that survives cropping). Everything else — wardrobe, set, light, pose — is a coordinate, and coordinates are supposed to change.
Two rules keep the datum honest. First, anchors are phrased as measurements, not opinions: “long dark-brown hair in a loose fishtail braid” survives generation; “beautiful hair” is re-interpreted on every job. Second, the datum is versioned. When you deliberately evolve the character — a new hairstyle arc, a new signature — save the new datum as version two and date it, so older sets remain reproducible on demand.
Working from the datum
Production then becomes calm, mechanical work. Pair the datum with three to five scene lines that share one setting and light setup. Generate wide at the standard model’s 6-credit price, cull to the best third, and only then spend on edits, swaps and upscales. When a frame comes back off-character, diagnosis is quick: either a scene line contradicted an anchor (a “short bob” scene line fighting the datum’s braid) or an anchor itself is phrased too loosely to hold.
What the datum cannot do
It cannot rescue a character who was never actually decided. If your anchors are adjectives — gorgeous, stunning, perfect — no system will hold her, because there is nothing fixed to measure against. Decide the woman on paper first. The datum is not where the creativity happens; it is where the creativity is surveyed in, so everything built on it agrees.