This page provides information on the V-Ray Volume Grid Channels tab.

 

Page Contents

 

Overview


The input file loaded for the Volumetric Grid must be generated from the source program with channels mapped in such a way that VRayVolumeGrid can read them correctly. The V-Ray Volume Grid Channels tab contains the the 3rd party Channel mappings and controls for Content Smoothing.

 


 

UI Path: ||Select V-Ray Volume Grid|| > Properties viewport > V-Ray Volume Grid Channels Tab

 

 

 

3rd Party Channel Mappings Parameters


 



V-Ray VolumeGrid is based on Phoenix FD and in its core, it supports the following channels:

Liquid/Temperature – Uses the liquid or temperature channel.
Smoke – Uses the smoke channel with a predefined analytical formula.
Velocity – Uses the magnitude of the velocity channel.
Speed – Uses the magnitude of the velocity channel.
RGB – Uses a three channel color.
Fuel – Uses the fuel channel.

 

Other applications might use different names for these channels. When loading f3d/vdb files, V-Ray Volume Grid tries to automatically make the conversion to the supported channels. If a channel is not mapped by default, you can manually set it to a channel in the this section.

Reset channel mappings to defaults – Returns all channel mappings to default values.

Smoke from – Dropdown to choose the Smoke channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Temperature from – Dropdown to choose the Temperature channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Fuel from – Dropdown to choose the Fuel channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Velocity.x from – Dropdown to choose the Velocity.x channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Velocity.y from – Dropdown to choose the Velocity.y channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Velocity.z from – Dropdown to choose the Velocity.z channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Color.R / U from – Dropdown to choose the Color.R / U channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Color.G / V from – Dropdown to choose the Color.G / V channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

Color.B / W from – Dropdown to choose the Color.B / W channel to load its data from a 3rd party channel mapping (only used with OpenVDB / Field3D).

 

Content Smoothing Parameters


 

 

 

Temperature smoothing enabled – Enables the Temperature channel to be filtered.

Smoke smoothing enabled – Enables the Smoke channel filter.

RGB / UVW smoothing enabled – Enables RGB / UVW smoothing.

Fuel smoothing enabled – Enables the Fuel channel smoothing filter.

Velocity smoothing enabled – Enables the Velocity channel smoothing filter.

 

Distributed rendering


A common problem with setting up DR is that the V-Ray Volume Grid might look for the cache files in a local machine directory. However, at the start of a network render, the scene file is copied to all render machines on the network to a new location, e.g. C:\Users\user\AppData\Local\backburner\Jobs\, while cache files are not automatically sent to the host machine. The cache files are not sent because on one hand they may be very large to the point where they could overload the disk space of the host, and also because in many cases not all of them are actually used in the rendering. This is why when rendering begins, if the hosts look for the cache files in a directory that was originally on the local computer, the cache files won't be found.

The solution is to move the cache sequence to a shared folder on the network or a mapped network drive, and set its path in the Input panel using a network-visible UNC input path (a path that starts with \\). You can also browse from the Input panel's path options.

If you are not using a UNC path, and instead your path points to a drive on your local computer, you will receive a message that states "You are using local machine Input path with distributed rendering!".