VGGT-XR natural and real 360 evaluation v0.3.0

This extension replaces the visually confusing rainbow analytical demo with a natural furnished analytical room and adds a real-capture heldout-position test using the pinned official ZInD sample protocol.

Natural analytical v2 (30 heldout views):

• PSNR 22.7171 dB
• SSIM 0.8012
• LPIPS 0.2308
• Improvement over natural v1: +3.4966 dB / +0.0256 / -0.1127

Real ZInD room 09, pano 5 held out from inference and optimization:

• SH0 fixed-budget baseline: 18.7464 dB / 0.6700 / 0.5108
• SH3 quality path: 19.2660 dB / 0.6881 / 0.4148
• Delta: +0.5196 dB / +0.0181 / -0.0960

The archive contains two gsplat flythroughs, two heldout comparison figures, two Gaussian PLY files, and the machine-readable result JSON. It does not contain ZInD source panoramas. Real heldout views still show substantial blur; this is an honest prototype result rather than production-quality free-viewpoint reconstruction.

Archive SHA-256: E4C7D332DE8D003A44E52ABD71298508BAF852210FAB11561DA622EDE80188E4

Standalone demo videos

• vggt-xr-kitchen-highres-ba-672.mp4 — 672×672, high-resolution real kitchen reconstruction with training-only bundle adjustment.
• vggt-xr-natural360-quality-336.mp4 — 336×336, SH3 quality path on the natural analytical 360° room.
• vggt-xr-zind-real360-quality-336.mp4 — 336×336, SH3 quality path on the real ZInD panorama protocol.

These files are original CUDA gsplat renders. The ZInD source panoramas and model weights are not included.

VGGT-XR quality update v0.2.0

重建质量更新：

• 真实 SH3、局部 3-NN 尺度、means LR 衰减与受 120k/200k 硬上限保护的增密
• 真实图 518 几何推理、672 颜色监督、padding mask 与精确 K 变换
• 训练图 SIFT tracks + robust BA；全景按 ERP 共享刚体微调
• 冻结新位置测试和 seeds 42/43/44 完整结果

冻结测试：TinyNeRF PSNR 13.123 → 13.284；受控 360° 新位置 PSNR 8.617 → 14.343。真实 kitchen 只有训练视图证据，不作为 heldout 指标。包内视频均为实际 gsplat CUDA 渲染，不是 Unity 录像；包括两份标准 3DGS PLY、三段视频、对照图、研究与实测报告。

SHA256: 85361703727727D639DCE915F454D81FDD70A4C43A287B474CB82EABABC7E810