ANI210 – Wk12

This week I read an article discussing the usage of Unreal Engine in the Film industry, as well as VR cinema. Epic Games founder and CEO Tim Sweeney claims that Unreal Engine 4, through its possibilities in photorealistic rendering, will converge content between different forms of media (King and Articles, 2015). Unreal Engine 4 allows developers to create content ranging from 2D mobile games to VR and console through a complete suite of game development tools (Epic Games, 2016).

The promo video featured a two minute animation of a boy chasing his kite that reminded me a lot of our own cinematic project. The video features 30 frames per second real-time rendering in 100 square miles of diverse terrain, as well as 15 million procedurally placed pieces of vegetation. A huge part of achieving this is code and the Blueprints Visual Scripting system; a gameplay scripting system that allows one to create gameplay elements from within Unreal Editor using a node-based interface(Epic Games, 2016).

 

References
King, D. and Articles, M. (2015) Unreal encourages filmmakers to use its game engine. Available at: http://www.cartoonbrew.com/tech/unreal-encourages-filmmakers-to-use-its-game-engine-111708.html (Accessed: 10 December 2016).
Epic Games (2016) What is unreal engine 4. Available at: https://www.unrealengine.com/what-is-unreal-engine-4 (Accessed: 10 December 2016).
Epic Games (2016) Introduction to blueprints. Available at: https://docs.unrealengine.com/latest/INT/Engine/Blueprints/GettingStarted/ (Accessed: 10 December 2016).

ANI210 – Wk11

Physically Based Rendering Continued

The Fresnel Effect

This refers to the change of reflectivity based on the angle at which a surface is viewed. This means that there will be a higher reflection from a light source that hits a surface at a grazing angle rather than a perpendicular one. This phenomenon can be observed in real life such as a lake that produces higher reflectivity of the opposite shore when observed from a lower angle. This also means that the Fresnel gives brighter reflection near the edges of objects in real life, as well as PBR graphics.

pbr_theory_fresnel.png

An interesting component of the Fresnel Effect is that any smooth surface viewed at the right grazing angle acts as a perfect mirror. In a PBR workflow, the artist specifies the base reflectivity of an object which means the minimum amount of color of light reflected. Using the Fresnel Effect adds reflectivity over that value by calculating the required reflection at different angles.

Metals

Unlike other materials, metals have almost no diffuse reflection, with their reflection consisting almost exclusively of specular reflection. Due to this high reflectivity, light does not penetrated the surface so no scattering occurs and the result is a very shiny look. Metals also produce a colored tint on the reflected light, for example bronze, gold and silver appear in different colors.

Microsurface

Microsurface is the tiny detail and imperfections on a surface such as grooves, scratches, cracks and lumps. Although invisible to the naked eye, these imperfections have a considerable effect on reflection. In PBR, instead of computing microsurface detail directly which would be very taxing, a measure of roughness called “Gloss”, “Smoothness” or “Roughness”  is specified as a constant for any material.

References

Games, W. (2015) Physically based rering. Available at: http://blog.wolfire.com/2015/10/Physically-based-rendering (Accessed: 22 November 2016).end

LLC, M. (2014) PBR theory. Available at: https://www.marmoset.co/toolbag/learn/pbr-theory (Accessed: 22 November 2016).

 

 

 

 

 

 

 

 

pbr_theory_fresnel.png