| Rendering | Render Type
Defines how your scene will render using the mental ray renderer. You can control the rendering method, sampling, effects, and optimization.
To Display (do one of the following):
The Render Manager > mental ray (Global Renderer)
Set a current pass and choose Render Render Renderer Options from the Render toolbar.
Type |
Raytracing: Activates the raytracing rendering algorithm. If this option is selected, reflections and refractions can be rendered. If this option is deselected, transparencies that do not refract rays still work, as do environment maps. Scanline: Activates the scanline rendering algorithm, which is faster than raytracing but gives less realistic results. When the scanline option is selected:
Rasterizer: Optimizes motion blur rendering in scenes with a lot of motion blur. Setting the renderer type to Rasterizer provides you with special Sampling options discussed in the Motion Steps option group. |
These controls are available only when Unified Sampling is enabled. Unified sampling provides simple and consistent controls for all rendering algorithms. The number of samples taken for any pixel is always between Minimum and Maximum. The exact value within this range is determined mainly by Quality. You can also set Cutoff to stop taking more samples if the difference between sample levels is smaller than the cutoff value.
Aliasing (Raytracing & Scanline Only)
For more information, see Sampling Contrast and Antialiasing, Sampling, and Filtering Tips & Tricks [Rendering].
For more information about optimizing motion blur rendering, see The Rasterizer [Cameras and Motion Blur].
The Enabled Features options allow you to toggle various types of shaders in order to achieve faster preview rendering. By default, all shader types are enabled. Types that you deactivate are ignored.
For more information on shaders and how to use them, see The Shader Library [Materials and Shaders].
Geometry Shaders |
Activates procedural geometry shaders. |
Displacement Shaders |
Activates Displacement shaders. |
Lens Shaders |
Activates Lens shaders. Used when a primary ray is cast by the camera. They may modify the ray's origin and direction to implement cameras other than the standard pinhole camera, and they may modify the result of the primary ray to implement effects such as lens flares. |
Volume Shaders |
Activates Volume shaders. Used to modify rays as they pass through an object to simulate effects such as clouds, smoke, and fire. |
Output Shaders |
Activates Output shaders. Operates on rendered images before they are written to a file and perform operations such as filtering, compositing with other files, and writing to different file formats. |
Hair Geometry |
Enables geometry hair rendering in the current pass. For more information about rendering hair, see Rendering Hair [Hair]. |
Lightmaps |
Activates Lightmap shaders. |
Render Type |
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Optimize |
Automatically sets parameters for heavy scene optimization. See Optimizing Large Scenes for Scalability [Rendering]. |
Restore Defaults |
Resets heavy scene optimization parameters to their default values. |
Quick access to the same rendering algorithms specified on the Rendering tab.
Activating the Memory Limit allows you to specify how much virtual memory mental ray can use to render your scene. When this setting is deactivated, no memory limit is set.
You can control whether reflection and refraction are rendered by enabling secondary rays. When secondary rays are active, you may need to adjust the Secondary Rays - Depth settings to accommodate the amount of reflection or refraction in the scene.
Depth refers to the number of times that a ray is reflected or refracted during the raytracing process. Each refraction or reflection of a ray creates a new branch in a ray tree.
Use higher values for a more accurate image, or use lower values for preview renders or to speed up rendering in scenes with little reflection or refraction.
Each frame is rendered one tile at a time. You can set the size of the tiles, as well as the order in which they are rendered.
Each frame is rendered one tile at a time. You can set the size of the tiles, as well as the order in which they are rendered.
Mesh Splitting Factor |
At render time, Softimage splits large objects into many pieces, each of which can be computed separately. It then sends a minimal amount of object data to the mental ray renderer which, in turn, uses a system of callbacks to request only portions of the object that it needs. The splitting factor affects the size (in triangles) and number of pieces that are created when the mesh is split. The default value of 1 splits a given mesh into the number of pieces that the underlying computations determine to be appropriate. Lowering the factor value to, say, 0.5 doubles the number of pieces, but halves their size. For more information, see Mesh Splitting [Rendering]. |
Visible Geometry Side |
By default, both faces of an object are rendered — those whose normals are facing the camera as well as those that are not. If you like, you can render just one face of an object. In this instance, the other face is "culled" (ignored). For example, if you select Front, only the polygons facing the camera are rendered. You should select this option if the back faces of the object are not influential in the scene. To ensure the highest–quality image, you should select Both. You should also make sure to select Both if you are rendering a double–sided transparent object. |
Sample Displacement Before Rendering |
This option can help speed up displacement rendering by providing mental ray with the correct bounding boxes for its calculations. The presampling increases the startup time when rendering the displaced object, but the actual rendering itself is much faster. The overall benefit can reach a performance factor of three. However, for quick previews when you want to get the first pixels as quickly as possible, regardless of the time it takes to complete the image, you may want to disable this option. The default is on. When enabled, mental ray performs a rough displacement on the object before rendering in order to obtain a correct bounding box for its calculations. This is particularly helpful if the maximum displacement parameter is set very low. (Geometry Approximation > Displacement > Max. Displ.) When disabled, mental ray takes the object's current bounding box (samples the original non-displaced mesh) and the maximum displacement, and uses that to decide whether or not the object is a part of a tile being rendered. In this case, if the maximum displacement is set too low, then you may end up with the object missing from some of the rendered tiles. |
Motion-Based Displacement Quality |
When set to a value greater than 0.0, this option allows you to automatically control the amount of displacement detail rendered on an object based on how fast the object is moving in screen space. The automatic reduction of displacement detail on moving objects has a significant impact on rendering performance and memory consumption by cutting down on the typically huge amount of tessellation data that gets generated. The displaced geometry should have a geometry approximation property applied to it and motion blur must be enabled for the render region and/or the render pass. See Applying and Editing Geometry Approximation [Scene Elements] and Defining and Rendering Motion Blur [Cameras and Motion Blur]. For fast moving objects, you can set the motion-based displacement factor to achieve images of comparable visual quality with fewer displacement details as compared to static or slow moving objects. Though it is possible to tweak displacement approximation on a per-object basis, this approach can be time-consuming and not very practical. In addition, the calculation of standard displacement approximation does not take into consideration that an object can have different amounts of motion across its different parts. Motion-Based Displacement Quality provides an automatic way of adjusting the displacement quality according to the amount of motion for a given object part. The geometry is reduced only in areas of the object with strong motion. Setting this option to 0.0 turns off this feature and there is no reduction of displacement detail based on motion. A value of 1.0 is the default and results in an acceptable compromise between quality decrease and rendering acceleration. Values greater than 1.0 further reduce the displacement detail for a given unit of motion, and values less than 1.0 raise the quality towards the static case. With a value of 1.0, the simplification of geometry takes effect for motion of approximately 16 pixels per frame. On slower moving objects, use higher values. For example, a value of 8 reduces the geometry in the areas of an object moving at the speed of 2 pixels per frame. |
Shutter |
You should first set the shutter Scene Render Options Property Editor for the scene to define the point in time when the geometry and its motion transformations and motion vectors are evaluated: this data is pushed to mental ray. See Scene Motion Blur Settings [Cameras and Motion Blur]. Once an appropriate shutter interval is set, you can then use the mental ray Shutter and Delay options to tweak the size and length of the motion blur trails (without re-evaluating the geometry and its motion data). These options allows you to quickly "dial-in" settings, if needed, although they are not particularly accurate. A value of 1 for Shutter causes mental ray to use the full length of the geometry's motion transformations and motion vectors as specified by the Speed option for the scene. |
Delay |
A non-zero delay offsets the motion blur trails. |
Convert Textures to Memory Maps
When a texture is memory-mapped, it means that the texture is never loaded into memory. Instead, it is accessed directly from disk whenever a shader uses it. When used properly, memory mapped textures can speed up rendering considerably.
The Convert Textures to Memory Maps options allow you to override the Rendering Preferences options for converting your image clips to memory mapped format at render time. For more information about working with memory-mapped images, see Using Memory-Mapped Textures [Texturing].
Rendering Preferences |
Opens the Rendering Preferences [Preference Reference] so that you can view your settings. |
[convert memory mapped] |
Specifies whether images are converted to memory-mapped (.map) format at render time. Choose one of the following: Use Preferences: converts images to .map format based on the preferences defined in the Rendering Preferences property editor. Enabled: .map files are generated and used when you render the pass, regardless of whether or not automatic .map file conversion is activated in the rendering preferences. Disabled: .map files are not generated when you render the pass, regardless of whether or not automatic .map file conversion is activated in the rendering preferences. Previously auto-generated .map files are not used when rendering the pass as long as you maintain this setting |
You can select a filter type for the post-rendering filter process that can be applied to the completed image. For each pixel, mental ray uses the values of the surrounding pixels to remove aliasing. The type of the filter determines how the surrounding pixels are weighted when calculating their average.
For more information, see Setting Sample Filtering [Rendering].
The Color Control parameters allow you to activate various basic image processing options that are then performed during rendering. The following processes are available:
Maximum Motion |
Sets a cap on the motion vector data being output with any motion or raster motion channel. This value specifies the maximum length (measured in pixels) allowed for the motion vectors. |
Compensate For Object Motion |
When on, motion compensation dynamically adjusts the shutter offset and close values so that the object is placed at (or as close as possible to) the location where it would normally appear if there was no motion blur enabled. When off, there is no compensation and the object is always placed at the shutter close position. This option only affects the on-frame shutter modes when rendering to motion or raster motion render channels. For details, see Scene Motion Blur Settings [Cameras and Motion Blur]. |
For more information, see Setting the Global Ambient Occlusion Options [Indirect Illumination].
Rays |
When ambient occlusion is enabled, and the Number of samples is set to 0.0 in the Ambient Occlusion shader, then Rays is the value used for the number of rays to cast when computing the ambient occlusion at the current shading point. As long as the ambient occlusion shader has its Number of samples set to a positive non-zero value, then the Rays value is ignored. |
Final Gathering is another way mental ray can calculate global illumination without photons. It calculates both direct and indirect lighting, using rays cast from the object's pixels rather than from the light.
For more information about setting up for final gathering renders, see Final Gathering [Indirect Illumination].
Depending on the final gathering mode you are working with you will need to set a combination of the following Accuracy options which are the main settings used to control the quality of a final gathering render.
For more information, see Setting Final Gathering Accuracy Options [Indirect Illumination].
View Dependent |
Specifies whether the Minimum and Maximum Radius values are measured in scene units or in pixels. The effect of activating this option is to cast fewer final gathering samples for objects that are farther from the camera. |
Number of Rays |
Defines how many rays are fired from each pixel to calculate the indirect illumination. Use low values to tweak the effect (around 10-30) and increase for the final render (>100). |
Interpolation Options: Final gather points are expensive to compute for every illuminated point, so mental ray uses the cached values of existing final gather points for interpolation of any additional final gather points that may be required to complete the effect. Min Radius, Max Radius, and the number of final gather Points are the parameters used specifically for interpolating these additional final gather points. For more information, see Setting Radii and Points for Interpolation [Indirect Illumination]. |
|
Points |
Available for Multiframe and Automatic final gathering modes. The minimum number of precomputed final gathering points that are used for interpolation of the indirect illumination. |
Max Radius |
Available for Multiframe, Expert, and Legacy final gathering modes. Max Radius defines the maximum distance in which a final gather result can be interpolated or extrapolated without spawning new rays. If there are too few final gather points within the Max Radius limit, then more final gather rays are shot and a new final gather point is computed. Very low values (<1) will increase render times but yield higher quality renders. |
Min Radius |
Available for Multiframe and Automatic final gathering modes. Min Radius defines the minimum distance within which a final gather result must be used for interpolation or extrapolation. It is normally set to 10% of the maximum radius. Very low values (<1) will increase render times but yield higher quality renders. |
The Falloff options limit the length of final gathering rays to a distance of Stop in world space. If no object is found within a distance of Stop, the ray defaults to the environment color. The Start parameter defines the beginning of the linear falloff range. Any objects at a distance between Start and Stop will fade towards the environment color.
For more information, see Setting the Final Gathering Falloff [Indirect Illumination].
Enable |
When enabled, Refinement Passes provide a progressive update (in three passes) of how the final gathering is being rendered. The passes are rendered using the mental ray Tile Size, instead of the usual final gathering tile order. Refinement Passes are most useful when used in conjunction with the final gathering Visualize option. |
The Presample Density, sample Filter Size, and Sampling Contrast are options that can help to smooth out and fine-tune the final gathering effect to some extent, but they are not substitutes for tweaking the Falloff settings.
For more information, see Setting the Final Gathering Sampling Options [Indirect Illumination].
Maximum Sample Normal Deviation
These settings are similar to the Raytracing Depth settings, but apply only to final gathering rays. They specify the number of times a given ray is reflected or refracted.
For more information, see Setting the Final Gathering Trace Depth [Indirect Illumination].
Reflection |
Specifies the maximum number of times a final gathering ray can be reflected in a scene. |
Refraction |
Specifies the maximum number of times a final gathering ray can be refracted in a scene. |
Diffuse |
Specifies the number of additional diffuse bounces for final gathering. For example, a value of 1 provides a single extra diffuse bounce, for a total of two bounces. The overall effect of additional bounces is to brighten the final gathering effect, though the effect is somewhat more localized than the effect of increasing the final gathering Sampling Contrast (see Trace Depth.) |
Combined |
Specifies the number of times a final gathering ray can be reflected and/or refracted in a scene. The Combined value should not be less than the sum of the Reflection and Refraction values. |
Bounces are defined by the Trace Depth Diffuse value. The irradiance part obtained from first bounce final gather is multiplied by this color. Note that this affects single bounces only (Diffuse value of 0).
Bounces are defined by the Trace Depth Diffuse value. The irradiance part obtained from secondary bounce final gather is multiplied by this color. This color takes effect only when the Diffuse value is greater than 0, meaning that there is more than a single bounce.
Defines how the final gathering map file is used.
Defines the name of the file to be used as a final gathering map. You can build the file name using Tokens and Templates.
Displays the fully resolved file name and output path for the final gather map. The map file name is appended to the scene output path defined in the Scene Render Options Property Editor.
For information on how to work with irradiance particles, see Irradiance Particles [Indirect Illumination].
For more information, see Setting Accuracy and Interpolation for Irradiance Particles [Indirect Illumination].
These options are not available when Final Gathering is enabled.
For more information, see Storing Indirect Light from the Environment [Indirect Illumination].
For more information, see Using the Irradiance Particle Map [Indirect Illumination].
[map file template] |
Defines the name of the file to be used as a particle map. You can build the file name using Tokens and Templates. |
Particle Map File Resolved Path
[map file resolved path] |
Displays the fully resolved file name and output path for the particle map. The map file name is appended to the scene output path defined in the Scene Render Options Property Editor. |
Indirect Illumination Algorithm
For information about importons in general, see Using Importon Maps [Indirect Illumination].
For more information about using importons with irradiance particles, see Storing Irradiance with Importons [Indirect Illumination].
The following options will increase render time significantly, but will yield better photon effects.
The following options calculate global illumination within a volume, as defined by a volume shader.
Map File Name |
Defines the name of the file to be used as a Photon Map. If an invalid path is defined, the render will fail and abort. You can build the file name using Tokens and Templates. |
Rebuild |
When on, the Photon Map is recalculated at each rendered frame. |
The following options allow you to render alternative representations of your scene that provide visual information about various parameters.
Defines how a scene will be exported to a render archive (*.mi2) or an object render archive (*.mia).