TRIMOTION - USER DOCUMENTATION

Installation

1. Download the addon as a ZIP file (Trimotion.zip)

1. In Blender 4.0 - 5.0+, go to Edit > Preferences > Add-ons

1. Click Install... and select the Trimotion.zip file

1. Enable the addon by checking the checkbox next to "Animation: Trimotion"

1. The addon panel appears in 3D Viewport's N-panel under Trimotion tab

Quick Start

1. Import Mocap: Load your high-fps mocap animation (BVH, FBX, etc.)

1. Select Armature: Click on your animated rig

1. Open Panel: Press N in 3D Viewport, find Trimotion tab

1. Analyze: Click "Analyze Animation" to see current keyframe count

1. Choose Method: Select "RDP (Smart)" for best results

1. Set Strength: Choose "3x (Moderate)" as a starting point

1. Simplify: Click "Simplify All Bones"

1. Review: Check the reduction statistics and play animation

Action & Slot Management (Blender 5.0+ Compatible)

Action Dropdown

• Click dropdown to switch between actions

• Click action name to rename it inline

• [+] button creates new action

• [X] button unlinks action (doesn't delete it)

NEW: Slot Management (Blender 5.0+)

• Slot dropdown appears below Action dropdown (Blender 5.0+ only)

• Select slot to choose which animation variant to work with

• [Duplicate] button creates new slot in current action

• [X] button unassigns slot from object

• Action = Animation data container

• Slot = Links animation to specific object

• Use dropdown to select/switch slots

• Multiple objects can use different slots from the same action

Simplification Methods Explained

RDP (Ramer-Douglas-Peucker) - RECOMMENDED ✨

• RDP Sensitivity: 0.1-10.0 (default 1.0)

• Lower = more keyframes kept, higher quality

• Higher = more aggressive reduction

Key Pose (Experimental) 🎨

• Key Pose Sensitivity: 0.1-5.0 (default 1.0)

• Lower = keeps more transition frames

• Higher = removes more, keeps only key poses

• Detects local extrema (peaks/valleys)

• Finds direction changes

• Identifies significant acceleration

• Fills gaps in non-linear sections only

• Sets interpolation to LINEAR for clean curves

Decimate

Adaptive

• Adaptive Sensitivity: 0.1-10.0 (default 1.0)

• Lower = stricter error tolerance

• Higher = allows more error, more reduction

Blender Clean

NEW: Advanced Features

Frame Range Limiter 🎯

• Use Frame Range checkbox enables range limiting

• Use Scene Range (default ON) - uses Timeline's Start/End frames

• Custom Range - set your own Start/End frames manually

• From Action: Sets range to action's keyframe range

• From Playhead: Sets start frame to current timeline position

• Keep intro/outro intact, simplify middle section

• Simplify loop cycles without touching transition frames

• Preserve hand-keyed sections while cleaning mocap parts

Smooth Curves 🌊

• Smooth Factor (0.0-1.0, default 0.5): How much to blend with neighbors

• 0.0 = no change

• 0.5 = balanced smoothing

• 1.0 = full average with neighbors

• Iterations (1-10, default 2): Number of smoothing passes

• More passes = smoother curves (but may lose detail)

• Applies weighted moving average to keyframes

• Blends each keyframe with its neighbors

• Respects frame range settings (if enabled)

• Noisy mocap data from cheaper systems

• High-frequency jitter in finger/facial animation

• After aggressive simplification to smooth transitions

• Before simplification to reduce noise spikes

Frame Rate Converter 🔄

• Source FPS: Original frame rate (0 = auto-detect from scene)

• Target FPS: Choose from presets or custom

• 24 fps (Film)

• 25 fps (PAL)

• 30 fps (NTSC)

• 60 fps (Games)

• 120 fps (High)

• Custom (1.0-240.0)

• Rescales all keyframe timings proportionally

• Preserves interpolation types and handles

• Updates scene render FPS automatically

• Handles fractional frame rates (e.g., 29.97)

• Convert 120fps mocap to 30fps game animation

• Match animation timing to different project frame rates

• Adjust imported animation to target platform

Batch Operations 📦

• Finds all armatures with animation

• Applies same settings to all

• Shows total keyframe reduction across all rigs

• Respects frame range settings

Settings Reference

Strength Levels

• 1x (Mild): 10-30% reduction, highest quality

• 2x (Light): 30-45% reduction, very high quality

• 3x (Moderate): 45-65% reduction, high quality ⭐ RECOMMENDED

• 4x (Strong): 65-80% reduction, good quality

• 5x (Very Strong): 80-90% reduction, acceptable quality

Workflow Examples

Example 1: Rococo Full-Body Mocap (100fps)

1. Import Rococo BVH (typically 15,000+ keyframes for 3 seconds)
2. Select armature
3. Click "Analyze Animation" (shows 15,000 keyframes)
4. Method: RDP (Smart)
5. Strength: 3x (Moderate)
6. Click "Simplify All Bones"
7. Result: ~5,000 keyframes (67% reduction), near-identical quality
8. Export to Unity/Unreal with optimized file size

Example 2: Making Editable Animation

1. Import Rococo BVH (typically 15,000+ keyframes for 3 seconds)
2. Select armature
3. Click "Analyze Animation" (shows 15,000 keyframes)
4. Method: RDP (Smart)
5. Strength: 3x (Moderate)
6. Click "Simplify All Bones"
7. Result: ~5,000 keyframes (67% reduction), near-identical quality
8. Export to Unity/Unreal with optimized file size

Example 3: Facial Animation Cleanup

1. Select facial rig
2. Enter Pose Mode (Tab)
3. Select facial bones only
4. Method: RDP (Smart)
5. Strength: 2x (Light) - be conservative with facial
6. Click "Simplify Selected Bones"
7. Review and adjust if needed

NEW Example 4: Simplify Middle Section Only

1. Select armature with animation
2. Enable "Use Frame Range" in Advanced section
3. Set Start: 50, End: 200
4. Method: RDP (Smart)
5. Strength: 4x (Strong)
6. Click "Simplify All Bones"
7. Result: Frames 1-49 and 201+ untouched, middle simplified

NEW Example 5: Smooth Noisy Mocap

1. Select armature
2. Analyze animation - notice jittery curves
3. Go to Advanced → Smooth Curves
4. Factor: 0.5, Iterations: 3
5. Click "Smooth Animation Curves"
6. Then simplify with RDP 3x for optimal result

NEW Example 6: Convert Frame Rate

1. Import 120fps mocap animation
2. Go to Advanced → Frame Rate Converter
3. Source: 120 (or leave at 0 for auto-detect)
4. Target: 30 fps (Games)
5. Click "Convert Frame Rate"
6. Animation now plays at 30fps with correct timing

Example 7: Batch Processing Multiple Characters

1. Import multiple animated characters
2. Don't select anything (or select any object)
3. Method: RDP (Smart)
4. Strength: 3x (Moderate)
5. Go to Advanced → Batch Operations
6. Click "Batch Simplify All Rigs"
7. All armatures in scene processed simultaneously

Tips & Best Practices

General

• ✅ Always save your file before simplifying (Ctrl+S)

• ✅ Use "Analyze Animation" first to understand your data

• ✅ Start with 3x RDP - works for 90% of cases

• ✅ Test on one bone first using "Simplify Selected Bones"

• ✅ Duplicate actions ([+] button) before simplifying for backup

By Animation Type

• Facial animation: Use 2x strength, be conservative

• Body animation: Use 3x-4x strength for good optimization

• Finger animation: Use 2x + smooth curves for best results

• Background characters: Use 4x-5x for maximum optimization

Advanced Techniques

• Key Pose method: Creates animator-style editable curves

• Check Graph Editor after simplification to verify quality

• Extreme optimization: Simplify in stages (3x, then 2x on result)

• Noisy mocap: Smooth first (3 passes), then simplify

• Frame Range: Simplify loops without touching transitions

• Batch mode: Process entire scene for consistent results

NEW: Workflow Combinations

1. Smooth → Simplify → Smooth: Best quality for noisy data

1. Frame Rate Convert → Simplify: Match target platform first

1. RDP → Key Pose: Reduce data, then make editable

1. Simplify with Range: Preserve hand-keyed intro/outro

Performance Notes

• Decimate method is ~5x faster than RDP for very large datasets

• Frame Range limiting speeds up processing

• Batch mode is efficient for multiple rigs

Requirements

• Blender 4.0.0 or later (tested through 5.0+)

• Works with all armature types

• Compatible with BVH, FBX, and any keyframed animation

• Blender 5.0+ Slot support included

• No external dependencies required

Built-in Manual

• Getting Started guide

• Action & Slot explanation

• Method descriptions

• Strength guide

• Advanced features overview

• Quick tips

Troubleshooting

"No bones selected" error

• Make sure you're in Pose Mode (Tab key)

• Select bones in the viewport or outliner

• The addon now supports both Blender 4.x and 5.0+ selection APIs

Blender 5.0 slot issues

• Use the slot dropdown to assign a slot

• Click [Duplicate] to create new slot if needed

• The addon auto-assigns first slot when action is selected

Frame range not working

• Enable "Use Frame Range" checkbox first

• Check Start/End values are correct

• Use "From Action" button to auto-set range