In this lesson, you will learn how to leverage Post-Process Materials to composite cinematic sequences by manipulating screen-space buffers, allowing you to achieve artistic visual consistency that transcends standard engine render settings.
Beyond the Final Render
While standard Color Grading and LUTs (Lesson 19) are essential for final looks, Post-Process Materials grant you pixel-level control over the final render buffer. In a cinematic pipeline, you often need to composite elements that aren’t natively in the scene, such as simulated film grain, chromatic aberration, or stylized frame overlays, without baking them into your geometry.
By using the PostProcessInput0 node in a Material set to the Post Process domain, you gain access to the rendered scene image. You can then perform math on the pixel colors—such as masking, blending, or distortion—before the frame is sent to the display.
Implementing a Stylized Frame Composite
For a cinematic sequence, you might want to apply a "viewfinder" effect or a custom vignette that reacts to the scene's brightness. You can achieve this by multiplying your input buffer by a procedural mask.
// Simplified logic for a stylized vignette mask
float2 uv = GetDefaultScreenUV();
float2 center = float2(0.5, 0.5);
float dist = distance(uv, center);
// Apply mask to the scene input
float3 sceneColor = Texture2DSample(PostProcessInput0, PostProcessInput0Sampler, uv).rgb;
float vignette = smoothstep(0.8, 0.2, dist);
return float4(sceneColor * vignette, 1.0);
The Power of Layering
You can chain multiple Post-Process Materials within a PostProcessVolume to build complex composites. By managing the Priority and Blend Weight of these volumes, you can transition between different "film stocks" or visual styles dynamically as your camera moves through the scene. This allows for seamless transitions from a high-fidelity realistic look to a stylized, cinematic-specific visual mode without editing your material instances or lighting setup.
Key Takeaway: Post-Process Materials allow you to treat the final frame as a canvas, enabling the artistic application of screen-space effects to ensure your cinematic sequences maintain a unified, polished aesthetic.