The Render Options window contains all settings for Render Mode, CPU Usage, and Render Quality. These options are specific for the Still Image, Animation and KeyShotXR output.
The Default render mode simply allows you to render immediately after adjusting your render output settings or, if using KeyShot Pro, to send your render to the render queue.
The Background render mode option allows you to run the render in the background and continue working. Note: the Real-time View will be paused by default when the render is started. Select Render and un-check Pause Real-time Render to un-pause the Real-time View and continue working.
Send to Network
If you use KeyShot Network Rendering, the Send to Network render mode allows you to send your render to the KeyShot Network Rendering Monitor. Make sure the Monitor is installed and running to send a job to be rendered on the network. Visit the KeyShot Network Rendering Overview for more information.
For Default and Background render modes, the CPU Usage setting allows you to specify how many CPU cores you want to utilize for rendering your project. Selecting Use Realtime CPU Settings will use the CPU Usage settings defined on the KeyShot Ribbon.
KeyShot has three output options for quality based on your needs.
The Maximum Samples option controls how many times the image or animation frame will be calculated and refined. Each additional sample will further smooth out noise/grain in the image. This option uses the same rendering technique as you see when working in the Real-time View. (This technique is also used in Maximum Time option, but differs from the method used in Custom Control option.)
Samples This controls how many times each pixel in the rendered image is calculated for increased accuracy. Too low of a value will result in an image that has excessive noise. Increasing samples will reduce the noise, however, increasing this setting too high will increase render times without a noticeable difference in quality.
Samples Per Frame The Maximum Samples option will read Samples Per Frame when the Animation tab is selected under the Output section. This option is ideal for animation output as it guarantees that each frame will be rendered at the same quality. Therefore, as the animation plays through the frames you will not see changes/flickering in shadows or noise patterns on materials.
How many samples should I use?
Generally speaking, a simple scene will require fewer samples and a scene with more complex lighting and materials will require more samples. Start low and increase the samples if you still see noise or the render looks grainy. Before rendering out an animation using Maximum Samples, test your samples with a still image render first.
Samples and Resolution
A sample calculates the color of a pixel. There is a point of diminishing returns where you increase samples past the point of added quality, and just increase the render time.
Something important to be aware of is that as you increase the resolution of your image or animation, each pixel covers relatively less area of the image. This means you can use a lower samples setting when rendering at higher resolutions. Note that this does not apply to rendering with area lights, caustics or interior mode as increasing samples while using those features will still increase the quality.
This method is typically preferred over the time-based output for animations, as some frames may require substantially more time to reach the same quality level as levels of detail and complexity change through the course of your animation. Using the time-based output will lead to more noise in the more complicated frames.
The Maximum Time option for render quality will progressively refine the render for the amount of time set. This option uses the same rendering technique as what you see in the Real-time View. This technique is also used in Maximum Samples option, but differs from the method used in Custom Control option.
When rendering an animation, you may set the maximum time for each frame to render, or set a total duration for the entire animation.
The Custom Control option allows control over all quality settings available in KeyShot. This mode typically produces smoother results in areas of high noise or shadow.
Samples This will control the amount of rays per pixel that will be sent into the environment to gather information to determine that pixel’s final shade. It is best to control this setting per material and set a value between 8 and 16 in the render settings. For information on samples and setting samples per material, please see the section on roughness and glossy samples.
Ray Bounces Ray bounces are the number of times rays of light are calculated as they bounce around a scene. For a detailed explanation and examples please see the section that covers ray bounces in the Real-time settings.
Anti Aliasing Anti aliasing is a method for smoothing out jagged edges that are created by pixels. Since pixels are made up of squares, they can produce a jagged look where edges meet. Anti aliasing smooths out these edges. In most cases, the default value of 1 is sufficient.
Shadow Quality Shadow quality will control the shadow quality for ground shadows. This can be tuned in real-time to determine what value is necessary. Please see the section on shadow quality found in the real-time settings.
Global Illumination Quality This will control the quality of all indirect light. Increasing this value can dramatically increase render time. It is rarely necessary to set a value above the default value of 1. If Global Illumination is turned off, this parameter will be grayed out. For more information and please see the section on detailed indirect illumination in real-time settings.
Pixel Blur This will apply a slight blur to the image to reduce the overly sharp look that computer generated images can have. Higher values will have more blur. This does not increase render time.
DOF (Depth of Field) This will control the quality of depth of field if it is enabled in the camera tab. Increasing this value will have an effect on render time. For production quality a value between 3 – 5 is recommended. If Depth of Field is not activated, this parameter will be grayed out. Please see the section on cameras for more information on depth of field.
Caustics Increasing this value will improve the samples and quality of the caustics. If caustics are not enabled, this parameter will be grayed out. Please see the section on caustics for more information.
Sharp Shadows This will allow sharp shadows to be cast across 3D geometry when the lighting scenario would create a sharp shadow. It is more accurate to have this checked and it is enabled by default. It is generally recommended to leave this on.
Sharper Texture Filtering This will attempt to preserve detail in textures when viewed at grazing angles. For example, imagine being eye level with a wood table and seeing the wood grain compress together. Detail can get lost in the compressed areas. This setting reduces the loss of detail. This feature can increase render time so enable only when using textures with glancing angles.
Global Illumination Cache Disabling GI Cache replaces the potential dirty shadows and black spots with noise. Increasing GI quality will reduce the noise. Increasing the samples will also help in reducing the noise.