Deferred Shading pipeline in DX12 (WIP)
​I’m working on a project in DirectX 12 using deferred shading. In this approach, I first render scene attributes—position, normals, albedo, specularity, glossiness, and emissiveness—into a G-buffer. Then, in a separate pass, I perform lighting calculations, optimizing performance by avoiding redundant shading operations. This technique allows for efficient handling of multiple dynamic lights in complex scenes while maintaining high rendering quality.
Development Specifications:
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Engine: D3D12 (C++)
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Platform: PC (Windows)
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Development time: 1 Month (WIP)
Table of Contents (Click the title to go to section)
Deferred Shading Pipeline
Deferred shading pipeline
G-Buffer Generation
The G-buffer in the engine's deferred rendering pipeline is designed to capture and store various surface information as separate render textures, optimizing the lighting pass and enhancing visual fidelity. This setup includes:
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Position texture: Stores world-space coordinates for each fragment, enabling accurate lighting calculations based on object depth and spatial relationships.
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Normal texture: Captures surface normals in view space, essential for accurate lighting, shading, and effects like normal mapping.
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Albedo texture: Contains base color data without lighting, defining the diffuse appearance of surfaces.
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Specular / Glossiness / Emissive texture: Stores reflectivity information, determining how much light is reflected based on the material properties. Controls the sharpness of specular highlights, allowing materials to range from rough to mirror-like surfaces. Holds self-illumination data for surfaces that emit light, enhancing scenes with glowing effects.
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By separating these attributes into distinct render textures, the G-buffer enables efficient lighting calculations during the lighting pass, reducing redundant computations and supporting multiple dynamic lights with minimal performance impact. This approach ensures high-quality rendering of complex materials and lighting effects in the deferred pipeline.
Scene
Position
Albedo
Normal
Spec / Gloss / Emissive
Lighting Calculations
In the lighting pass of the deferred rendering pipeline, lighting calculations are performed by sampling data stored in the G-buffer. During this pass, the scene's lighting is computed separately from geometry rendering, allowing for efficient handling of multiple dynamic lights.
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The G-buffer contains separate render textures for position, normal, albedo, specular, glossiness, and emissive data. In the lighting pass, the shader retrieves this information for each pixel to calculate how light interacts with surfaces. The lighting is typically divided into diffuse, specular, and emissive components, which are combined to produce the final illuminated scene.
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This approach enables efficient lighting with a high number of dynamic lights by decoupling geometry processing from lighting calculations, improving performance and visual quality in complex scenes.
Point light calculations
G-Buffer viewer tool
I created a tool that lets me view the G-buffer in real time during the deferred rendering pipeline, making it much easier to see how different types of data are stored for lighting calculations. With this tool, I can separately visualize each G-buffer render texture—like position, normal, albedo, specular, glossiness, and emissive maps—and see how they’re generated frame-by-frame.
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Being able to inspect the G-buffer in real time helps me debug and optimize the rendering pipeline more effectively. I can quickly spot issues like incorrect normals, texture sampling problems, or unexpected lighting artifacts. It also allows me to fine-tune materials and lighting setups by immediately seeing how changes impact the scene. Overall, this tool has been incredibly useful for diagnosing rendering issues and improving the deferred rendering workflow.
G-Buffer viewer