Redshift Renders Faster with Biased Rendering & GPU Acceleration

Redshift supports severalbiased global illuminationtechniques including brute force GI, photon mapping with caustics, irradiance cache, similar to irradiance map and final gather, and irradiance point cloud which is similar to importons – a kind of virtual particle - and light cache. Users choose the techniques that work best for particular scenes.

Anout-of-core architectureis used for geometry and textures, allowing you to render massive scenes that would otherwise not fit in video memory. GPU renderers are typically limited by the available VRAM on the video card. They can only render scenes where the geometry and textures fit entirely in video memory, creating challenges for rendering large scenes with many millions of polygons and gigabytes of textures.

With Redshift, rendering such scenes is possible with off-the-shelf hardware because it supports geometry instancing. Massive scenes with large numbers of repeating objects like grass or trees, for example, can be rendered efficiently with low memory overhead. Because Redshift runs on the GPU with minimal CPU usage, the machine remains responsive while rendering.

Redshift also supportsrender proxies. Previously exported geometry may be placed in scene but is only loaded into memory when it is needed at render time.  Using proxies, scenes can be rendered that might not load in the host software otherwise.  Like regular geometry, Redshift proxies can be instanced - again, making rendering scenes with billions of instanced polygons possible.

Redshift has aprogressive rendering modethat allows interactive previews of scenes without waiting for GI prepasses.  This mode uses progressive refinement, showing draft quality results almost immediately while continuously refining the quality over time.

Thenode-based shader systemsupports complex shading networks, and surface, photon, environment, light and lens shaders, as well as various bidirectional reflectance distribution function, or BRDF, lighting models. This gives scope for developing photorealistic results or very stylized looks. Photoreal looks, in particular, can be achieved with physically correct surface shaders, lights, photometric or IES lights, and a physical sun and sky system.

Point-based sub-surface scatteringis used for fast, smooth rendering of realistic skin, marble, milk and other substances. A photographic exposure lens shader comes with tonemapping and camera exposure parameters, and a depth-of-field lens shader is included. High-quality texturing is achieved throughelliptical filtering. In contrast to point sampling, elliptical filtering performs an image lookup within an elliptical area that contains many pixels. The pixels are averaged to the average colour returned as the result.

Several optimizations in Redshift help limit noise without losing performance by automatically adjusting the number of samples used throughout the renderer, based on trial-and-error techniques. Consequently, more samples are taken where they are needed, and fewer where they have less benefit.

Redshift runs directly within the host software applications, so you can use it as you would the native renderer. From the host software, Redshift translates the geometry, cameras, lights, materials and other relevant properties, making it easier to learn. Redshift currently includes plugin integration with Autodesk Maya and Softimage, running on Windows. Integration with Autodesk 3ds Max and support for Mac OSX and Linux are coming soon. OpenCL support is planned for a future release.  

Redshift requires anNVIDIA GPU with CUDAcompute capability 2.0 or higher and 1GB VRAM or more.

Glassworks’ Babies Sing for Cadbury

Glassworksanimation and VFX studio in London, Barcelona and Armsterdam, used Redshift to make an intriguingcommercial for Cadbury. Glassworks has been evaluating Redshift as an addition to Arnold and some other renderers they use, and said the quality and stability of the renderer is excellent. “The render options are presented in a way that is familiar and modern - unified sampling, various global illumination mechanisms and physically-based render options are intuitive and easy to use,” saidAlastair Hearsum, Head of 3D at Glassworks.

“The integration into Softimage is excellent with support for many of the native shaders and render parameters but what is more impressive is the stability and fluidity of the render region which allows rapid and easy iteration. It's very easy to arrive at a look quickly with Redshift. The render speed produces many more iterations in the development phase, allowing us to really fine tune a look.

“From a look point of view, the renders look great - from rapid Depth of Field to smooth motion blur and extra high sampling rates through to the subsurface and volumetric effects. For such a relatively young renderer it has already covered a lot of ground."