When Ultra Render is on, you can access Ultra Render settings in the camera properties panel to adjust the quality, render speed, and overall look. Changes you make to these settings will be visible in the camera preview window.
Note: If changes to not appear to be applied, trigger the render using the play button in the camera preview window, or by resizing the window.
Max Rays
The Max Rays setting refers to the maximum amount of light rays to be calculated in a path by the path tracing engine. The higher the number of rays, the more realistic the render. Increasing rays also increases the render time.
Max time
This setting allows you to set the maximum time the Ultra Render engine can take to render a frame. Rendering speed will vary depending on the computer power and internet speed, so setting a max rendering may result in varying levels of quality.
Exposure
The amount of light in the image
Rays per Frame
This setting affects the speed that the engine processes light. By increasing the rays per frame, you are increasing the amount of pixels that may render simultaneously. This will allow the engine to produce higher quality renders in less time. Increasing rays per frame will also require more computer memory, so unless your machine has a very high GPU it is best to keep this number set below 10 to avoid performance issues.
Clay Shade Mode
This mode displays a clay version of your scene, allowing you to evaluate lighting on its own (without effects of materials/reflections).
Firefly Threshold
“Fireflies” are the white or high contrast pixels that appear scattered over an image when rendering. These occur due to poor light estimation by the rendering engine. Fireflies are commonly seen near light sources or reflective surfaces. Increasing the max rays and the rays per frame will allow for more precise estimation of light.
The firefly threshold setting cuts off, or clamps, bright pixels. This will help remove fireflies. A high threshold will allow for more bright pixels, while a low threshold will cut off dimmer pixels.
This applies to all pixels in the scene, so setting the threshold too low may also dim pixels that are intentionally bright. However, fireflies are uncommon in brighter scenes.
Clay shade mode
As the name suggests, this hides texture maps and objects appear as clay models.
Normal map invert
There are 2 formats of normal maps: OpenGL and DirectX. The 2 formats are read in opposite directions, so bumps or dents in your materials may appear inverted in when using Ultra Render, depending on the format of your maps. If your maps are in DirectX format (or if they appear to be inverted) turn on the “Invert Normals” setting.
Tone Mapping Options
Tone mapping adjusts the contrast levels and colour profile of your image to improve the appearance on digital screens. Each lookup table (LUT) presets will produce a different look, mimicking film photography, game design, and other styles.