Two-Stage SFT
SciForma fine-tunes FLUX.2-klein-base-9B on SciFormaPile in two stages. Stage 1 trains all 9B parameters on the full 656K generation pairs with resolution bucketing to keep batches spatially homogeneous across widely varying aspect ratios. Stage 2 initializes from Stage-1 EMA weights and co-trains on 244K High-quality pairs together with the 71K editing triplets, so a single checkpoint serves both generation and editing through a concat-then-prune design that adds no new parameters.
244K + 71K
Stage 2 Gen + Edit
140K / 90K
Stage 1 / 2 Steps
Multi-Dimensional Direct Preference Optimization
SFT leaves axis-specific artifacts such as missing components, garbled labels, and broken arrows, and these failure modes are near-independent across the three axes (inter-axis ρ < 0.2). MD³PO pairs each winner with dimension-anchored losers, one per axis, and couples them through an InfoNCE-style contrastive objective. The loss only vanishes when the policy prefers the winner on every axis simultaneously, and a softmax over per-axis reward gaps automatically concentrates gradient on whichever dimension is currently weakest.
M-DPO ablation on SciFormaBench-2K. Text axis benefits most (+3.16 pts).
- Conjunctive objective. Loss only vanishes when the winner beats every axis-anchored loser at once.
- Auto-focusing gradient. A softmax over per-axis logits sends the largest update to the failing axis.
- InfoNCE view. Equivalent to InfoNCE with D axis-anchored hard negatives.
- Standard DPO limit. Reduces exactly to standard DPO when D = 1.
Iterative Refinement via Editing
At inference time a VLM critic inspects the generated diagram against its structural inventory and flags concrete defects, which are compiled into a priority-ranked edit plan. SciForma-9B applies each atomic edit through the same editing branch trained in Stage 2, and the loop repeats for a fixed number of rounds or stops early once the critic reports no remaining structural errors, yielding the closed-loop refinement shown below.
Closed-loop editor. Defect detection, priority-ranked edit plan, SciForma-9B targeted inpainting, global verification. The loop terminates when the structural inventory is satisfied.