Difference Between Ambient Occlusion And Global Illumination

Ambient Occlusion:

Ambient= Immediately Surrounding

Occlusion=Blockage

Ambient Occlusion is a shading technique that is using in 3d modeling, animation, and rendering. This technique always come up with a realistic result. You can say this technique is using to expose every scene in animation and rendering.

Moreover, If the scene looks too bright ambient Occlusion makes it too soft and realistic.

Uses of Ambient Occlusion:

1. Ambient Occlusion uses to expose each scene in a render
2. Ambient Occlusion uses to make an overall scene more realistic
3. Ambient occlusion: uses to generate feature shadows
4. Ambient occlusion: uses to present every detail of a model in 3 dimension or directional source

Global illumination:

Global illumination has alternative names like Indirect illumination and indirect light.

Global illumination indicates the bouncing and blending of lights from one surface to another in a scene. Or it is a process that simulates indirect lights in a scene. To make a realistic sense during rendering and animation global illumination is the best technique.

Types of Global illumination:

There are types of Global illumination:

1. Radiosity
2. Photon mapping
3. Caustics

Direct Global Illumination:

Whenever a light source directly illuminates an object in a

a scene Direct Global illumination will occur, or it always considers light from the source in a scene used for shading and detailing of an object( Direct global illumination technique shadow map or

shadow volume).

Direct illumination is also called local illumination.

 

In-direct Global illumination:

When light is transmitted by an object and illuminate

another object the in-direct Global illumination will occur. So the light source will not directly illuminate an object when you are talking about

indirect global illumination. 

Global illumination is also a very advanced form of Ray-tracing that is using in computer graphics.

                          

How to get an approach to these options?

• Go to render setting and click on effects you will get the different option of Global Illumination and Ambient Occlusion on the same bar.

• Each effect has various properties to play with and get a result of demand. you can set colors and gradient, Ray length Max and min, Dispersion, accuracy, contrast, and much more according to the required instruction

Ambient Occlusion and game development :

     In games, Ambient Occlusion plays an important role to create shadows of character and different gaming assets to give them a realistic look. Many games like ROME 2 total war, call of duty, ghost reconds wildland, Shadows of tom raider, and uncharted are using this technique to give a more detailed look to their character and overall game environment.

   

Uses of Ambient occlusion:

1:Ambient occlusion uses to calculate light. The light is coming from the direct resource as well as from indirect resource in a scene

2:It is used to make reflection, refraction, and shadows in a scene

3:It is used for photorealistic result in a 3D Render

Types of Ambient occlusion:

There are four main types of ambient occlusion

1. SSAO( Screen Space Ambient occlusion)
2. HBAO(horizon based ambient occlusion)
3. HDAO(high definition Ambient occlusion)
4. VXAO(Voxel-accelerated ambient occlusion)

• SSAO( Screen Space Ambient occlusion)

This concept was developed by Vladimir Kajalin and used for the very first time in 2007 in a video game.In Computer Graphics SSAO( screen-space ambient occlusion) is a technique that is used to measure the efficient and approximate effect of ambient occlusion in real-time

• HBAO(horizon based ambient occlusion)

HBAO(horizon-based ambient occlusion) is a step up for the faster and approximation of true ambient occlusion. It is the upgrade version of SSAO. It was introduced by SIGGRAPH tech conference NVIDIA in 2008 for the very first time. This technique used a physically-based algorithm that gives highly realistic results in practice.

• HDAO(high definition Ambient occlusion)

HDAO (high definition Ambient occlusion) an alternative technique that is used in ambient occlusion. This technique is used in games to provide detailed value to the different objects of the game. You may need high power graphic cards in your PC’s to run up.

• VXAO(Voxel Accelerated Ambient Occlusion)

This is another exciting technique of ambient occlusion. No doubt this is a revolutionary technique that always gave a stunning result in-game graphics. The pros and cons of this technique depend on the machine they are running on. Because for its best result you must need a huge graphic power.