The Best New Features in the Redshift Renderer Update
Discover the new lighting and animation features that make us excited about the latest version of Redshift.
Here are the biggest new features we are excited about.
1. Specular Light Ray Bending through Refraction
One of the biggest new features is the way Redshift computes direct lighting. We are particularly excited about this feature as the look of glass has always seemed a bit off compared to other options. As Slater says,
Traditionally, light rays that are blocked by a refractive or rough object ‘shadow-caster’ do not bend, they simply continue in a straight line towards the light. This is great for getting fast and clean lighting using Multiple Importance Sampling, but not great for realism, especially when trying to model something like a lens. Usually, this omission is not that noticeable, but it can be really noticeable when using a Dome Light environment map to illuminate your scene.
Historically, the specular rays from dome light environment maps were not being refracted. In the image above, 2.6.10 now allows users to control light bending in area lights, which can dramatically affect the realism in certain situations (glass and refractive surfaces).
To avoid excessive noise, Redshift created three new modes:
- Never – Light rays will not bend through refractive of rough shadow-caster objects. (Equivalent to versions leading up to 2.6)
- Auto – If there is too much noise, the rays will not bend. If there is not much noise, they will bend. If it’s determined somewhat noisy, a blend of both results will be created.
- Always – Light rays will bend regardless of noise.
Old scenes will default to Never, new scenes will default to Auto. For legacy scenes or non-arch-vis renders, there are also global overrides to disable this feature completely.
2. Area Light Directionality
With this latest update, users can now create a barn door effect, meaning they can control the spread of an area light.
This new parameter controls the cone of light, where a spread of 1.0 gives 180-degrees of light (default), 0.5 offers 90-degrees, and a spread of 0.0 is a 0-degree directional light. This will be particularly useful for getting a more focused throw but has no effect on specular.
Redshift has noted that this initial release is not optimized for volumetric or single scattering light, so there may be more noise than anticipated. They are working on improvements for further updates.
3. Better Bump Mapping Fidelity
To get better results from bump mapping, there are two new techniques used to get better renders. A global mip-map bias to bump and normal maps, and a bug fix from bump-mappings.
As Slater shows in these examples,
To demonstrate, below is a simple example rendered in 2.5.72 of a bump-mapped surface extending to the horizon. The bump texture is a finely detailed brick map, heavily tiled so the lighting appears noisy. See how the lighting detail appears a little ‘soft’ and loses definition over distance?
Below shows the same scene using the default settings in 2.6.10. See how the bump appears sharper and lighting detail is better preserved overall:
4. New Proxy Animation Features
This latest update gives users the ability to set the number of animation loops that a proxy will run as well as giving artists control to offset the animation.
This is particularly useful for creating all sorts of effects where the cache needs to be offset to look more realistic, like trees blowing in the wind or a running horde of zombies.
5. Better Denoising
Redshift continually works to get better denoising with Optix and Altus. We found the denoiser to work better on still renders, rather than animations. But future updates will likely continue to improve.
For more on denoising, check out our Denoiser Battle Royale, where we looked at the best options we had available in our current workflow.
6. More to Come in 2.6 and 3.0
Redshift has also confirmed there will be more 2.6 features in the near future, including cryptomatte and multi-step deformation blur. Any other major features will be part of Redshift 3.0.
Zompolas teased the following in the forum,
We’re actively working on this and a good few things are done already: bloom, glare and lens flare. We’re also making the photographic exposure lens shader “realtime” so you can adjust tonemapping and other settings from the RV and without the renderer re-starting. But there’s a good amount of cleanup and determining details like camera selection, batch rendering, AOV, etc.
When the implementation of these remaining things gets a bit closer, we’ll commence the necessary teasing!
General Redshift Updates
There were also a series of general updates and fixes made to the build for Maya, Houdini, Katana, and Cinema 4D. Here are the changes that affect C4D users.
- Addressed an issue where the IPR would not detect modifications in the ShaderGraph editor, when the Cinema 4D viewport was hidden
- Addressed an issue where the renderable setting of layers would produce different results for instances, when compared to the built-in renderers
- Improved modification detection for particle emitters.
- Addressed an issue where tessellation and displacement could not be overridden in proxies.
- Addressed a crash related to the management of UserData.
Improved the particle random object distribution algorithm so that it provides consistent results irrespective of the particle ordering. The older algorithm is still available under the “Random (Legacy)” option.
- Added an Offset and Loop options to the animation tab of RSFile parameters.
- Lifting the 128 volume grids per ray limitation. Please see this for more info.
- Added new option to RS area lights to allow for physically correct specular through refractions
- Added new global ‘Additional Bump Bias’ option to increase bump and normal-map fidelity by default
- Removed license checkout/checkin during renderer initialization
- Fixed bug that could trigger a ‘gridSizeX’ limit assert when rendering many AOVs
- Fixed bug that could prevent the correct uv channel from being used by proxy material overrides
- Added new ‘exposure’ option to RS lights
- Switched to using HSV internally for the ColorCorrection node to fix bug with HDR colors
- Added support for enabling ‘Abort on License Failure’ by setting environment variable REDSHIFT_ABORTONLICENSEFAIL=1
- Increased internal shader count limit to allow for more complex shader graphs
- Raising the limit of irradiance point cloud and irradiance cache working memory to 4GB (from 1GB)
- Fixed bug that would prevent point-based SSS from being correct behind transparencies
- Fixed bug that could cause lighting artifacts when global volume scattering shaders are assigned
- Added support for ‘Multiple Scattering’ ray contribution slider on all lights
- Fixed bug that could cause a crash when rendering scenes with custom AOVs and toggling between IPR and bucket rendering
- Fixing potential point-based SSS artifacts on fast-moving motion-blurred geometry
- Fixed bug that would produce incorrect tri-planar projections for instanced objects, or when in IPR mode
- Proxy ColorCorrection shader backwards compatibility
- Added support for area light directionality ‘spread’
- Enabled new improved bump mapping fidelity by default
- Improved bi-cubic texture filtering to remove a hard band that could sometimes occur
- Improved quality of light and shadow texture sampling by removing a sometimes over-aggressive mip-map choice that could lead to ‘light leaking’
- Fixed rare SSS hierarchy crash that can occur with multiple GPUs when the render is interrupted
- Fixed bug that could potentially cause a crash when rendering with custom AOV shader passes