FrameVGGT: Frame Evidence Rolling Memory for streaming VGGT

Streaming Visual Geometry Transformers such as StreamVGGT enable strong online 3D perception but suffer from unbounded KV-cache growth, which limits deployment over long streams. We revisit bounded-memory streaming from the perspective of geometric support. In geometry-driven reasoning, memory quality depends not only on how many tokens are retained, but also on whether the retained memory still preserves sufficiently coherent local support. This suggests that token-level retention may become less suitable under fixed budgets, as it can thin the evidence available within each contributing frame and make subsequent fusion more sensitive to weakly aligned history. Motivated by this observation, we propose FrameVGGT, a frame-driven rolling explicit-memory framework that treats each frame's incremental KV contribution as a coherent evidence block. FrameVGGT summarizes each block into a compact prototype and maintains a fixed-capacity mid-term bank of complementary frame blocks under strict budgets, with an optional lightweight anchor tier for rare prolonged degradation. Across long-sequence 3D reconstruction, video depth estimation, and camera pose benchmarks, FrameVGGT achieves favorable accuracy--memory trade-offs under bounded memory, while maintaining more stable geometry over long streams.