BOOTCAMP: REDSHIFT
Redshift is one of a new breed of Gpu-based render engines that combine speed with great flexibility
Mike Griggs takes us through the benefits of working with this Gpu-based render engine
GPU (graphics card) rendering is now no longer the young upstart of the CGI industry. For many freelancers and studios, the speed benefits of rendering with the GPU are now matched by feature sets that are equal to the traditional CPU render engines which have long been dominant. And leading this insurgence is Redshift (www.redshift3d.com).
Redshift is unusual within the GPU rendering market as it is the first biased render engine. This offers much more flexibility and ways to optimise an image than an unbiased engine, which tries to accurately model the physics of light.
Redshift also offers a solution to the amount of data a GPU rendering solution can handle, which is normally dependant on the size of the computer’s graphics card. Redshift has excellent out-of-core memory management which utilises the rest of the computer’s resources when needed. This means that scenes will render rather than fail, which can be the story with other Gpu-based render solutions. In the latest version of Redshift automatic memory management intelligently balances the load between graphics cards if there is more than one installed.
Redshift originally started as a third-party render solution for Softimage, and using the same licence Redshift can now work with Autodesk Maya, 3ds Max, Sidefx’s Houdini and Maxon’s Cinema 4D, with the Foundry’s Katana soon to be supported.
One of the reasons that Redshift has been adopted by so many freelancers and studios alike is that it is so quick and reliable in final render, with tools such as a wide range of AOV’S (render outputs) and robust particle system support. With the improvements that have been made with the recent release of version 2.5 of the software, Redshift now offers a complete render solution across multiple digital content creation platforms.
01 Learn to work with nodes
Redshift’s material system relies on a nodal interface. This allows single elements such as a texture map to be used multiple times throughout a texture, which is much more efficient than more traditional methods. The other great thing about using this nodal method is that, although the UI may be subtly different between host applications, the methodology is always the same, which means when learning Redshift a lot of the techniques are transferrable.
02 the redshift ipr And renderview
The Redshift IPR is the interactive preview window for Redshift, although this is gradually being superseded by the Redshift Renderview which is much more powerful and enables users to preview AOVS and render samples. The Renderview can also be used to create snapshots and adjust colour settings, as well as save images and start renders. To work on specific areas of a scene use the Render Region tool to select an area for Redshift to concentrate on.
03 Progressive And final render
The Redshift IPR and Renderview both default to rendering in progressive mode. For final rendering Redshift uses the bucket render option which can also be previewed in the IPR and Renderview. Bucket rendering works best when needing to preview subsurface scattering and global illumination options. There can also be subtle differences in lighting between the two modes, so always make sure to preview in bucket before final render.
04 redshift special nodes
Redshift comes with a range of nodes that can aid easy asset creation quicker than using the first-party options within the host 3D application. A great example of this is the Triplanar node which projects imagery on an object’s X, Y and Z axis without the need for UVS, which can be a huge time saver for artists, especially those new to 3D, and is great for more experienced artists for simple scene setups for product shots.
05 redshift smoothing
Redshift has its own smoothing and displacement tools which can keep a scene easy to manipulate while providing perfectly rendered geometry. The tessellation and displacement need to be activated in the object’s properties. Any texture-based displacement has to first be processed through a displacement node to allow Redshift to decipher the image, which can either be a vector image or height-based black and white image such as a noise node.
06 redshift Lighting And camera settings
The lighting tools in Redshift include the standard set of Area, Dome and Spotlights. Redshift also comes with an excellent and extremely quick volumetric and fog system which is easy to set up. The camera in Redshift can render in several modes including stereo, fisheye and spherical amongst others. Depth of field is easy to set up, and because Redshift is GPU enabled there is hardly any hit in performance when it is enabled. •