Movie Render Pipeline

Offline cinematic rendering pipeline for high-quality frame output with deterministic time stepping and temporal accumulation.

Source: SparkEngine/Source/Engine/Rendering/MovieRenderPipeline.h

Overview

The Movie Render Pipeline renders cinematic sequences offline at arbitrary resolution and quality settings. Unlike real-time rendering, it steps the simulation deterministically at a fixed timestep, accumulates multiple sub-frames for anti-aliasing and motion blur, and writes each completed frame to disk.

The pipeline supports quality presets ranging from fast Preview (1x AA, no motion blur) to Cinematic (32x AA, 16 motion blur sub-frames). A DeterministicTimeController overrides the engine's delta time during rendering to ensure frame-perfect reproducibility. Optional warm-up frames allow particle systems, physics, and other time-dependent effects to settle before recording begins.

Output formats include PNG (8-bit RGBA), EXR (32-bit HDR), and TGA (uncompressed). Console variable overrides let you force maximum quality settings during the render without changing the game's runtime configuration.

Architecture

MovieRenderPipeline (singleton)
  +-- MovieRenderJob (active job state)
  |     +-- MovieRenderSettings (resolution, frame range, quality)
  |     +-- progress, timing, output file list
  +-- DeterministicTimeController (fixed dt override)
  +-- accumulation buffer (sub-frame blending)
  +-- callbacks (per-frame, completion)
  +-- completed jobs history

Render Loop

StartRender() --> [WarmUp frames] --> [Render frames]
                                        |
                  For each frame:       |
                    For each sub-frame: |
                      Step(fixedDt)     |
                    CaptureFrame()      |
                  --> Complete/Finalize

Key Classes

Class	Description
`MovieRenderPipeline`	Singleton managing offline render jobs
`MovieRenderSettings`	Configuration for a render job (resolution, quality, frame range)
`MovieRenderJob`	Active or completed job with state, progress, and output files
`DeterministicTimeController`	Overrides engine time with fixed delta for reproducible simulation

Usage

auto& pipeline = Spark::Rendering::MovieRenderPipeline::GetInstance();
pipeline.Initialize();

Spark::Rendering::MovieRenderSettings settings;
settings.width = 3840;
settings.height = 2160;
settings.frameRate = 24.0f;
settings.startFrame = 0;
settings.endFrame = 240;
settings.qualityPreset = Spark::Rendering::RenderQuality::Cinematic;
settings.outputFormat = Spark::Rendering::OutputFormat::EXR;
settings.warmUpFrames = 30;
settings.outputDirectory = "Renders/Scene01";

pipeline.SetFrameCapturedCallback([](int32_t frame, const std::string& path) {
    // Per-frame notification
});

pipeline.StartRender(std::move(settings));

// In the main loop:
pipeline.Update(deltaTime);  // Uses fixed dt internally
float progress = pipeline.GetProgress();  // 0.0 to 1.0

API Reference