Advanced Graphics Techniques

This section delves into sophisticated techniques used in modern graphics development to achieve stunning visual effects, enhance performance, and create immersive experiences.

Real-time Ray Tracing

Explore the principles and implementation of real-time ray tracing, enabling photorealistic lighting, reflections, and refractions directly within your applications. Learn how to integrate ray tracing with traditional rasterization for hybrid rendering approaches.

Ray Tracing Scene — Photorealistic lighting with ray tracing.

Key aspects covered:

Acceleration structures (e.g., BVHs)
Path tracing fundamentals
Denoising techniques
Hardware acceleration (e.g., RTX)

Global Illumination

Understand how to simulate the indirect lighting that bounces off surfaces, creating more natural and believable scenes. This includes techniques like:

Screen-Space Global Illumination (SSGI)
Voxel Global Illumination (VXGI)
Light Propagation Volumes (LPV)
Precomputed Radiance Transfer (PRT)

Example code snippet for a basic GI shader:


uniform sampler2D g_sceneDepth;
uniform sampler2D g_sceneNormal;
uniform sampler2D g_sceneAlbedo;
uniform vec3 g_lightDirection;

// ... (other uniforms and functions)

void main() {
    vec3 worldPos = reconstructWorldPos(gl_FragCoord.xy);
    vec3 normal = texture(g_sceneNormal, gl_FragCoord.xy).rgb;
    vec3 albedo = texture(g_sceneAlbedo, gl_FragCoord.xy).rgb;

    // Simplified indirect lighting calculation (e.g., ambient occlusion term)
    float ao = calculateAmbientOcclusion(worldPos, normal);

    vec3 directLight = max(dot(normal, -g_lightDirection), 0.0) * albedo * vec3(0.8);
    vec3 indirectLight = albedo * ao * vec3(0.2); // Basic indirect influence

    gl_FragColor.rgb = directLight + indirectLight;
    gl_FragColor.a = 1.0;
}

Physically Based Rendering (PBR)

Implement PBR workflows for creating materials that behave realistically under different lighting conditions. This involves understanding parameters like:

Albedo (Base Color)
Metallic
Roughness
Specular
Ambient Occlusion

PBR Material Example — Realistic material properties with PBR.

PBR Lighting Example — How PBR reacts to different lights.

Post-Processing Effects

Enhance visual fidelity with a range of post-processing techniques applied to the rendered image:

Tone Mapping
Bloom and HDR
Depth of Field (DoF)
Motion Blur
Color Correction and Grading
Anti-Aliasing (TAA, FXAA, SMAA)

A simple Bloom shader implementation outline:


// ... (texture samplers for the rendered scene)

float bloomThreshold = 0.8;
float bloomIntensity = 0.5;

float luminance = dot(texelFetch(g_sceneTexture, pixelCoord, 0).rgb, vec3(0.2126, 0.7152, 0.0722));
vec3 bloom = vec3(0.0);

if (luminance > bloomThreshold) {
    // Apply a Gaussian blur or separable filter to bright pixels
    // ... blur logic ...
    bloom = brightPixels * bloomIntensity;
}

finalColor = texelFetch(g_sceneTexture, pixelCoord, 0).rgb + bloom;

Compute Shaders for Graphics

Leverage the power of compute shaders for tasks beyond traditional rendering, such as:

Particle Systems
Simulation (fluids, cloth)
Image processing
Procedural content generation