Chapter 18: The Animation System
This is Part 6 of the Unity HDRP production guide, continuing from Part 5: Environments. This installment covers production and export: the animation system, Timeline and Cinemachine, the HDRP Water System, and final export with Unity Recorder.
18.1 What Makes Unity's System Different
Unity's animation system differs fundamentally from traditional 3D software (Blender, Maya, 3ds Max) through its modular, procedural approach:
| Aspect | Traditional software | Unity |
|---|---|---|
| Timeline | Linear, fixed frames | Modular, independent clips |
| Duration | Globally defined | Per object, independent |
| Transitions | Manual | Managed by a state machine |
| Interactivity | Preview | Real time |
Advantages of Unity's approach: animations are reusable across objects, transitions are automatic and conditional, it integrates natively with gameplay, and there's no global-duration constraint.
18.2 System Architecture
The Animator component (Add Component → Animator) is the base component on any animated object - the conductor coordinating its animations. The Animation Controller asset (.controller, Assets → Create → Animator Controller) is a node-based system managing animation states and transitions: States (Idle, Walk, Run...), Transitions (moves between states), Parameters (control variables: bool, float, trigger), Layers (stacked animation layers). Animation Clips (.anim) hold the keyframes - created in Unity, imported from FBX files, or shared across multiple objects.
18.3 Creating Animations
Open Window → Animation → Animation (or Ctrl+6). Workflow: select the object to animate, open the Animation window, click Create for a new clip, add properties to animate (position, rotation, scale, etc.), and place keyframes on the timeline. Methods: manual keyframing (click the diamond icon to add a key), Recording mode (the red button - any change creates a key), and Curves (editing interpolation curves directly). Almost anything is animatable in Unity: Transform (position, rotation, scale), components (light color, intensity...), materials (color, shader properties), and exposed script variables.
18.4 Advanced Animation Controller
In the Animator window (Window → Animation → Animator): drag clips in to create states, right-click a state → Make Transition, connect it to another state, and configure the transition's conditions. Parameters drive transitions: Float (speed, blending), Int (state index), Bool (conditions), Trigger (one-shot events). Blend Trees mix several animations by parameter - a walk/run blend by speed, directional blends (forward, left, right), or combined states.
18.5 Importing External Animations
Animations import from FBX files: select the FBX, open the Animation tab, and configure the clip list - Start/End (clip's start/end frames), Loop Time (looping), Root Motion (movement driven by the animation itself). Retargeting transfers animations between characters with similar skeletons via the Avatar system (Rig → Animation Type → Humanoid).
Chapter 19: Timeline and Cinemachine
19.1 Timeline
Timeline (Window → Sequencing → Timeline) is Unity's sequencing tool, similar to a non-linear video editor. To create one: select a GameObject (or create an empty one), click Create in the Timeline window, and name the Timeline asset. Track types: Animation Track (animation clips), Activation Track (enables/disables GameObjects), Audio Track (sound and music), Cinemachine Track (controls virtual cameras), Signal Track (custom events), Control Track (controls other Timelines). Clips can be dragged to reposition, stretched at their edges to change duration, blended by overlapping two clips for a transition, and right-clicked for trim/split/ease in-out options.
19.2 Cinemachine
Cinemachine (install via Window → Package Manager) is Unity's cinematic camera system, giving professional camera moves with no scripting. Core components: Cinemachine Brain (added to the Main Camera, orchestrates virtual cameras), Virtual Camera (a configurable virtual camera), Dolly Track (a rail for tracking shots), Clear Shot (automatically picks the best camera). Create a virtual camera via Cinemachine → Create Virtual Camera, then set its Follow (position target) and Look At (orientation target), plus a Body and Aim behavior.
| Body type | Description |
|---|---|
| Transposer | Fixed offset from the target |
| Framing Transposer | Keeps the target within a frame |
| Orbital Transposer | Orbits around the target |
| Tracked Dolly | Follows a rail |
| Hard Lock to Target | Identical position to the target |
| Aim type | Description |
|---|---|
| Composer | Keeps the target framed |
| Group Composer | Frames a group of targets |
| Hard Look At | Points directly at the target |
| POV | Manual rotation control |
19.3 Combining Timeline and Cinemachine
In Timeline, Add → Cinemachine Track, assign your camera's Cinemachine Brain, then drag Virtual Cameras in to create clips - transitions between clips automatically produce camera blends. For a dolly shot: Cinemachine → Create Dolly Camera with Track, position the track's waypoints, then animate the Virtual Camera's Path Position parameter in Timeline.
A typical sequence: a wide virtual camera plays for the first few seconds, overlapping into a close-up camera for a blended cut, then handing off to a dolly camera for a final tracking shot - Cinemachine handles each camera's weight (0→1, 1→0) automatically during the overlap to produce a smooth blend.
19.4 HDRP Water System
HDRP includes an advanced water system with wave simulation, reflection and refraction, created via GameObject → Water → Water Surface.
| Type | Description |
|---|---|
| Ocean | A large body of water with waves |
| River | Flowing water |
| Pool | A calm surface (swimming pool) |
Main parameters: Simulation (wave type and intensity), Appearance (color, transparency, scattering), Refraction (underwater distortion), Foam, Caustics (refracted light projections).
Chapter 20: Export and Finishing
20.1 Unity Recorder
Install via Window → Package Manager → Unity Recorder, then access it via Window → General → Recorder → Recorder Window. Interface sections: Recording Mode (Manual, Frame Interval, Time Interval), Recorders (the list of configured exports), and + Add Recorder to add a new one.
20.2 Export Types
Image Sequence exports a sequence of still frames - Source (Game View, Target Camera, Render Texture), Output Resolution (FHD, 4K, Custom), Media File Format (PNG, JPEG, EXR), Capture Alpha (include transparency). Movie exports a video file - MP4/H.264 for web and previews, WebM/VP8-VP9 for web with transparency. AOV Image Sequence exports separate render passes:
| Pass | Description |
|---|---|
| Beauty | Final image |
| Depth | Z-depth |
| Normal | Normals |
| Albedo | Color without lighting |
| Ambient Occlusion | AO |
| Motion Vectors | Motion |
| Specular | Reflections |
| Diffuse | Diffuse lighting |
20.3 Recommended Configuration
For cinematic renders: Format EXR 32-bit, Resolution 4K (3840×2160) or higher, Frame Rate 24 fps (film) or 30 fps, Color Space Linear. For AOV/compositing: Add Recorder → AOV Image Sequence, select every needed pass, Format EXR (supports HDR and multi-layer), Color Space Linear.
Production workflow: configure Timeline and animations, set render quality (max quality, AA, etc.), configure the Recorder with the needed passes, start recording, then import into your compositing software.
20.4 External Post-Production
| Software | Use | Strengths |
|---|---|---|
| Nuke | Professional compositing | VFX industry standard |
| After Effects | Compositing, motion | Versatile |
| DaVinci Resolve | Color grading, editing | Free, powerful |
| Fusion | Node-based compositing | Built into Resolve |
Working with passes: import the multi-layer EXR, separate passes as needed, adjust lighting via the diffuse/specular passes, add Depth of Field in post using the depth pass, add motion blur using the motion vectors, then finish with color grading.
Part 6 Summary
| Chapter | Skills covered |
|---|---|
| Ch. 18 - Animation | Animator, Animation Controller, clips |
| Ch. 19 - Timeline/Cinemachine | Sequencing, virtual cameras, Water System |
| Ch. 20 - Export | Unity Recorder, formats, AOV passes |
Key takeaways: Unity's animation system is modular, with independent clips; the Animation Controller is a state machine managing transitions; Timeline enables non-linear sequencing like an editing program; Cinemachine gives professional camera moves with no code; Unity Recorder exports images, video and AOV passes; and 32-bit EXR is the recommended format for compositing.
Part 7, next and last, covers Shader Graph, plus a keyboard shortcut and resource reference.