What is ray tracing?(What is, Concept and Definition)

Used in graphic design, ray tracing is the act of using the path light passes through pixels to create images.Ray tracing simulates the effects light rays have on objects they find.Images created with ray tracing tend to be of better quality and have a higher degree of realism, but take longer to complete and require more computing power.Therefore, ray tracing is used more frequently to create still images.

For example, ray tracing can be used on a film because images can be made in post-production, so they are time consuming.By contrast, video games require faster image rendering; so ray tracing is not the best option.

How does ray tracing work?

The

software called ray tracker simulates the journey of individual light rays from a virtual light source to a virtual camera lens.The virtual light ray can pass through volumetric atmospheres like fog or smoke, and interact with surfaces of materials such as metal, glass, or water, for example.Each of these objects is designed and modeled by artists and engineers to affect the appearance of the scene as depicted by the tracker Rays Advanced raytracers can apply additional calculations such as interreflection, radiosity, and caustics to simulate complex light behaviors.

How long does it take?

Ray tracing can generate very realistic images, but it is computationally expensive and therefore very slow.For example, each frame of the computer animated film Monsters University , released by Pixar in 2013, it required 29 hours to render.At 24 frames per second, the 110-minute movie has approximately 160,000 frames.Pixar used a massive render farm to distribute the calculation, completing it in a matter of months.On a single computer, the movie It would have taken four and a half million hours, 524 years, to finish rendering.

Not all renderers are ray tracers

Because it takes a long time to compute, ray tracing is often used for final rendering.Intermediate or preview renders are often done with "cheaper" renderers, which quickly produce a lower quality image.For example, Blender uses the Cycle Renderer to perform ray tracing, or Blender's Internal Renderer to quickly render non-photorealistic images.

Ray Tracing on the GPU

Traditionally, ray tracing is done by the CPU, not the GPU.The hardware of a GPU is designed to pump as many FPS (frames per second) as possible, to improve real-time graphics applications, like video games.By contrast, ray tracing is usually a slow process, sacrificing real-time speed for photorealistic quality.Therefore, ray tracing software is not designed to run on GPU hardware, and the GPU hardware is not designed for ray tracing.

However, on August 13, 2018, NVidia announced its new Turing graphics processing architecture, capable of real-time ray tracing.The first GPUs to use Turing's architecture, Quadro RTX, will be released.at the end of 2018.

Ray Tracing Software

The following are examples of ray tracing software available to download or purchase.

• Autodesk 3ds max-A proprietary 3D modeling, animation, and rendering application aimed primarily at CAD users, such as architects.


• Autodesk Maya: Similar to 3ds max, but with a focus on character animation.


• Blender: A free open source 3D modeling, animation, and rendering application.


• Bryce: a fractal landscape generator introduced in 1994.


• Cinema 4D-A procedural effects 3D rendering, animation, and modeling application for filmmakers and motion graphics artists, advertised as easy to learn.


• Houdini: a full-featured 3D animation app Simulated physics, fluid dynamics, and volumetric simulations.A limited version called Houdini Apprentice is available for students and enthusiasts to use for free.


• Lightwave-a 3D CGI application used to create motion graphics, special effects, and video games.


• LuxCoreRender: a free open source processor for Windows, macOS and Linux.


• POV-Ray (The Persistence of Vision Raytracer): A free open source processor that creates images from SDL (Scene Description Language), a complete Turing language with macro support.


• RenderMan: A cinema-quality processor developed by Pixar, used in movies like Incredibles 2 and Avengers: Infinity War .


• Visionaray: an open source cross-platform ray tracing library.


• YafaRay: a free and open source Monte Carlo ray tracker.

Additional resources