BVH Viewer

Purpose & User Intent: The BVH Viewer solves the problem of inspecting BVH motion capture data without a full 3D tool. Target users include 3D animators, game developers, VFX technicians, and researchers who export BVH assets from Maya, Blender, or motion capture systems. Use when you need to verify hierarchy integrity, map channels to joints, compare motion across takes, or prepare data for pipelines.

Core Logic & Features: The tool parses a BVH file, builds a joint hierarchy, and decodes per-frame channels into joint transforms. Required features: BVH parsing, hierarchy extraction, channel-to-joint mapping, per-frame transform computation. Advanced features (optional): unit scaling, coordinate conversion, frame range filtering, frame-rate normalization, joint remapping, and export of skeleton or motion summaries as JSON/CSV. It supports common BVH variants and reports structural mismatches.

Inputs & Outputs: Inputs include bvh_file (required), frame_rate (optional, fps), time_range (optional, start/end in seconds), and scale (optional). Outputs include skeleton_data and motion_data plus a summary with frame_count and duration. Validation requires a valid hierarchy with at least one motion channel; corrupted files yield parse errors and abort gracefully.

Algorithms & Calculations: Parsing builds a joint tree, records rest pose, and converts channels to per-frame transforms via parent-child composition. Global transforms are computed by concatenating parent transforms with local offsets. Optional interpolation handles missing frames when a time range is supplied; coordinate conversion may align up-axis with the target; scale multiplies distances.

Error & Edge Cases: Invalid file formats, missing root or essential joints, non-monotonic or zero frames, or excessive joint counts trigger structured errors with diagnostics. Large BVH files may require chunked parsing.

Industry/Region & Localization: BVH is a global standard; units are typically meters and seconds; frame rates vary; no locale-specific handling beyond numeric formatting.

Assumptions & Exclusions: Assumes BVH adheres to Biovision standard with defined hierarchy and channels. Excludes rendering, UI editing, or real-time streaming; focus is on data extraction, validation, and export-ready outputs.