System

The System rollout gives you access to various parameters including those that control V-Ray's rendering regions (buckets). The bucket is an essential part of the distributed rendering system of V-Ray. A bucket is a rectangular part of the currently rendered frame that is rendered independently from other buckets. Buckets can be sent to idle LAN machines for processing and/or can be distributed between several CPUs. Because a bucket can be processed only by a single processor, the division of the frame in too small number of buckets can prevent the optimal utilization of computational resources (some CPUs stay idle all the time). However, dividing the frame between too many buckets can slow down the rendering because there is some time overhead related with each bucket (bucket setup, LAN transfer, etc).

The System rollout also includes parameters that control the V-Ray raycasting acceleration structure. One of the basic operations that V-Ray must perform is raycasting – determining if a given ray intersects any geometry in the scene, and if so - identifying that geometry. By default, V-Ray uses Intel Embree raycaster.

The next subsection in the System rollout includes parameters for the frame stamp. The frame stamp is a convenient way to put some short text over the rendered images. It can be useful in many ways – for example, in network rendering, to quickly determine which frames were rendered by which machine. The frame stamp is one line of text, which appears at the bottom of the image.

The following subsection in the System rollout deals with Distributed rendering. Distributed rendering is the process of computing a single image over several different machines. Note that this is different from distributing the frame over several CPU's in a single machine, which is called multithreading. V-Ray supports multithreading, as well as distributed rendering. Before you can use the distributed rendering option, you must determine the machines that will take part in the computations. Both 3ds Max and V-Ray need to be properly installed on those machines, although they don't need to be authorized. You must make sure that the V-Ray spawner application is running on those machines - either as a service or as a stand-alone application. For additional information on distributed rendering, please refer to the dedicated Distributed Rendering section.

The next subsection deals with parameters for the V-Ray log. These parameters control the V-Ray messages window. During rendering, V-Ray writes various information in the file C:\VRayLog.txt. The messages window shows some of that information so that you can view it without the need to manually open that file. Each message can fall into one of four categories, which are colored in a different way in the messages window. Those categories are errors (colored in red), warnings (colored in green), informative messages (colored in white) and debug messages (colored in black).

The last subsection includes parameters that don't fall into the other categories and buttons to access other V-Ray settings. The following windows can be accessed through this rollout:

UI Path:  ||Render Setup window|| > Settings tab > System rollout (Renderer set to V-Ray)

The following parameters are visible from the System rollout when set to the Basic Render UI Mode.

Sequence – Determines the order in which the regions are rendered. Note that the default Triangulation sequence is best if you use a lot of dynamic geometry (displacement-mapped objects, VRayProxy or VRayFur objects) since it walks through the image in a very consistent manner so that geometry that was generated for previous buckets can be used for the next buckets. The other sequences tend to jump from one end of the image to another which is not good with dynamic geometry.

 Division method – Controls the way the image is divided into buckets and therefore controls the meaning of the Bucket width and Bucket height parameters. For more information on buckets, see the Bucket Image Sampler page.

Size – The Bucket width and Bucket height parameters are both measured in pixels. 
Count – The Bucket width and Bucket height parameters specify how many buckets are necessary to cover the whole image.

Post-effects rate – The frequency of post-effects updates, such as denoising and lens effects, during progressive rendering; roughly the percentage of time calculations are allowed to take compared to the total render time. Zero disables updates during progressive rendering. Larger values cause the effect to be updated more often. A value of 100 updates the post effects as often as possible. Values between 5 and 10 are usually sufficient. Viewport IPR always uses update rate of 100 unless the value is set to 0. If the value is 0, then the render is not denoised in Viewport IPR.

Auto-show post effects – When enabled, if force shows (turns on the toggle) all post-effects that are set for calculation (Denoiser, Sharpen/Blur, Lens Effects) in the VFB layer stack.

Dyn mem limit, mb – The total RAM limit for the dynamic raycaster, which stores dynamic geometry, such as displacement and VRayProxy objects. Set this to 0 to remove any limit (V-Ray takes as much memory as needed). The memory pool is shared between the different rendering threads. Therefore, if geometry needs to be unloaded and loaded too often, the threads must wait for each other and the rendering performance suffers.

Frame stamp – Turns the frame stamp on and off.

Edit box – Enter the text you wish to appear in the images. You can also use some special keywords, all of which begin with the percent symbol (%). The keywords are replaced by V-Ray with the corresponding value:

Add server – Allows you to manually add a server by entering its IP address or network name.

Edit server – Allows you to change the data about a render server.

Remove server – Deletes the currently selected server(s) from the list.

Resolve servers – Resolves the IP addresses of all servers.

Restart servers on render end – When enabled, the 3ds Max copy on the render servers is restarted once a DR rendering is finished. This may help to make distributed rendering more stable.

Save servers in the scene – When enabled, V-Ray stores the list of render servers into the 3ds Max scene. This is useful if the scene is later sent to Backburner for distributed rendering. In that case, instead of taking the DR servers list from the vray_dr.cfg file on the machine where the backburner server is running, the list is taken from the 3ds Max scene.

Max servers – Allows you to limit the maximum number of servers from the list to be included in distributed rendering. When set to 0, all listed servers are used.

Use local host – When enabled, the client machine (the one from which the user initiates the DR render) also takes part in the rendering calculations. If disabled, the client machine only organizes the DR process, sends rendering tasks to the render servers and displays the final result.

Render region/test resolution warning – When enabled, V-Ray displays a warning if the render region or the test resolution option is enabled before sending a job to the network. 

Transfer missing assets – Allows render servers to automatically download missing rendering assets from the client machine. This includes textures, V-Ray proxy files, IES profiles, GI solution caches (irradiance map, light cache), X-Ref scenes etc.

Use cached assets – This option tells the render servers to keep the downloaded rendering assets between different DR sessions. If disabled, the render assets are automatically deleted once the render server disconnects from the client machine at the end of the rendering. When enabled, assets are kept in a folder on disk. By default, it is named vray_assets_cache located in the temporary folder for the user that runs the V-Ray DR spawner. The location of the assets cache can be modified with the environment variable VRAY_ASSETS_CACHE_PATH. Modified assets are generally detected and re-transferred to the render servers even though they may already exist in the render servers' caches.

Cache limit type – Allows you to specify under what conditions the assets cache is cleaned up. The possible values are:

None – Assets are never deleted from the render servers' cache.
Age (hours) – Assets are kept for the specified amount of time. At the end of the rendering, the render servers deletes assets that have been transferred before the specified time limit. 
Size (GB) – When the size of the assets on a render server exceeds the specified amount, least recently used assets are automatically deleted at the end of each render until the folder size is less than the limit.

Cache limit value – The specific value of the limit for the asset cache. This is either hours or GB, depending on the value of Cache limit type.

The following parameters are added to the list of visible settings available from the System rollout when set to the Advanced Render UI Mode.

Reverse bucket sequence – Reverses the region sequence order.

Previous (render) – Determines what should be done with the previous image in the virtual frame buffer when rendering starts. Note that this parameter has no effect on the final result of the rendering; it is implemented simply as a convenient way to distinguish between parts of the current frame being rendered, and parts left over from the previous rendering. The possible values are:

Unchanged – No changes are made - the virtual frame buffer remains the same.
Cross – Every second pixel of the image is set to black.
Fields – Every other line of the image is set to black.
Darken – The colors in the image are darkened.
Blue – The previous image is tinted in blue.
Clear – Removes the previous frame for the VFB.

Conserve memory -Embree will use a more compact method for storing triangles, which might be slightly slower but reduces memory usage.

Default geometry – Internally, V-Ray maintains two raycasting engines: for static and dynamic geometry. This parameter determines the type of geometry for standard 3ds Max mesh objects. Note that some objects (displacement-mapped objects, VRayProxy, and VRayFur objects, for example) always generate dynamic geometry, regardless of this setting.

Static – All geometry is precompiled into an acceleration structure at the beginning of the rendering and remains there until the end of the frame. The static raycasters are not limited in any way and consume as much memory as necessary.
Dynamic – Geometry is loaded and unloaded on the fly depending on which part of the scene is being rendered. The total memory taken up by the dynamic raycasters can be controlled by the Dyn mem limit,mb parameter.
Auto – Some objects are compiled as static geometry, while others as dynamic. V-Ray makes the decision on which type to use based on the face count for an object and the number of its instances in the scene.

Frame stamp - Turns frame stamps on or off. The frame stamp records information about the scene as text on the rendered images. For example, frame stamps can be used with network rendering to record which frames were rendered by which machine. The frame stamp appears as one line of text at the top or bottom of the image.

Stamp textbox - Text entered into this field will appear in the images. Special keywords can also be used, as long as they begin with the percent symbol (%). The keywords are replaced by V-Ray with the corresponding value. The VRay Frame Buffer shows a list of such keywords.

Full width – When enabled, the frame stamp takes the whole width of the image, otherwise the stamp is only as wide as the text is.

Justify – Specifies the position of the stamp:

Left – The stamp is placed on the left of the image. 
Center – The stamp is centered. 
Right – The stamp is placed on the right side of the image.

Font – Allows you to choose a font and font attributes for the text in the frame stamp.

Log window – Determines the conditions for showing the log.

Verbose level – Determines what kind of messages are shown in the window:

1 – Only error messages. 
2 – Error and warning messages. 
3 – Errors, warnings, and informative messages. 
4 – All messages.

Log file – Determines the location and the name of the log file. The default log file is %TEMP%\VRayLog.txt

Memory tracking - When enabled, generates a memory usage report for textures and objects. For more information, visit the Memory Tracking page.

Output directory - Determines the location of the memory tracking files.

Show latest stats - Displays the last memory usage report generated.

Check for missing files – When enabled, V-Ray tries to find any missing files in the scene and puts up a dialogue listing them, if there are any. The missing files also are printed to the C:\VRayLog.txt file.

If this option is on, and you render the scene with distributed rendering, and if a render server detects missing files, it refuses to render the scene.

If the option is on, and you export a .vrscene file, and if there are missing assets, Standalone refuses to render the scene.