传统BA优化正式退场？Transformer取代BA优化，全局一致轨迹瞬间生成

TL;DR - A WeChat technical commentary (largely a promo for a paid 3D-vision study community) arguing that feed-forward Transformer models like VGGT are displacing bundle adjustment (BA) as an explicit, standalone optimization stage in multi-view reconstruction and SLAM. The claim matters because it reframes global consistency from an iterative back-end loop into a single differentiable forward pass.

• Cites VGGT as a pure feed-forward Transformer that outputs camera poses and 3D structure in one forward pass, compressing minute-scale iterative optimization to sub-second inference.
• Lists supporting works: SLAM-Former (CVPR 2025) replacing back-end optimization with global attention, BA-T (2026) using an iterative Transformer to emulate BA updates, and KV-Tracker (CVPR 2026) reaching ~30 FPS via KV caching.
• Argues BA is "internalized," not eliminated: VGGT gains further accuracy when stacked with differentiable BA, and SLAM-Former retains a global back-end module — geometric constraints persist as internal differentiable components.
• Content is opinion/marketing-heavy with no benchmarks, datasets, or quantitative comparisons; the bulk of the article advertises a "3D视觉从入门到精通" knowledge-planet course catalog (~6300+ members, 20+ video courses), so the technical claims are unverified here.