The article provides a list of recommended workflow that can help to avoid issues with Missing, Disconnected, Orphaned, or Self-duplicating Materials in Rhino. In case the issues reoccur despite following the workflow, please contact Chaos Support.
Table of Contents
General rule
Updating Rhino
With Rhino 7.13 there was a critical update concerning the material structure and how they are handled. The issues described in this article have been recognized to be partially related to this change. The problem might persist if a project has been first created with a Rhino version older than SR13/15 or contains imported content initially created using the specified version range. Therefore we highly advise making sure to update Rhino to its final available version.
The current Rhino version can be found in Help > About Rhinoceros
Available updates can be found in Help > Check for Updates
V-Ray should be enabled from start to finish
It is of high importance that V-Ray is installed and enabled during the entire working process with a project, from opening, altering, saving, to closing the file. Certain changes or actions executed without V-Ray being loaded may result in a list of issues, change of material types, loss of V-Ray data, material duplication, and others. Those issues will occur once the 3dm file is saved, closed, and later reopened.
In order to avoid the possibility of encountering those issues, make sure that V-Ray is active at the beginning (opening) of each project and right before the project is saved.
When opening a file
Avoid opening files by double-clicking
In Rhino world, opening via double click and opening via command/toolbar/menu are not equivalent actions. Certain events are not fired in the first case and vice versa and this can lead to some issues.
In the case of the V-Ray for Rhino plugin, the first time V-Ray loads after being installed, reinstalled, or updated, it takes a few seconds for it to load. In such cases, if a file is opened with a double click then Rhino will start and the file will open prior to V-Ray being fully initialized. This will eventually result in issues and some or all of the materials will become 'self-duplicating' ones. In such cases make sure to close the file without saving it and reopen it. To avoid this issue, make sure that you first open Rhino, select V-Ray Renderer, and wait for V-Ray to load. Once V-Ray is running, open a project from the File > Open or by using a command line.
Check for missing materials
Whether the issues have been encountered previously or not, we recommend using a safe workflow when opening any project files. Even if the Disconnected materials and/or Orphaned Materiasld warning is not displayed upon loading a file, we recommend spending a few seconds to load the Asset Editor to make sure all materials are loading and rendering properly. If the materials are missing and the message of the Disconnected materials appears make sure to close the file without saving it and reopen it again. If the issue occurred during the file loading, this should solve the problem. If the issue is not resolved, please contact Chaos Support and make sure to provide us with the information by following the instructions provided at the end of the article.
When saving a file
Backup your work files
In Rhino the autosave process is entirely independent of the normal saving process. The Autosave saves a copy of the file for an emergency. However, every new autosave overwrites the previous one. If the original file is saved and Rhino has closed without crashing, the autosave file is deleted and moved to the recycle bin.
In order to have a full backup of your work make sure that you have a healthy habit of saving your project in serialized separate files instead of having a single file that is saved over the old one. Upon starting a new project, choose the project name and add a number (for example Projectname_01) to help you track the project progress. When it is time to save your progress, make sure you avoid the “Save” option and instead select the “Save as” option and change the number following the project name ( Projectname_02 ) This is a healthy safe method that will allow you to regularly “backup” your work and if you encounter any issues, you will always have a previous version of the file.
Save Textures and Save Plugin data
When selecting the “Save as” option make sure that “Save small” is not selected by mistake. Once the “Save as” window is opened at the bottom the options Save Textures and Save plugin data should be checked by default. Make sure that those options have not been disabled.
V-Ray must be enabled before saving a file
If a project file is saved without V-Ray being enabled the project may become lossy. Upon reopening the file V-Ray material may no longer be applied to the scene object and groups. In such cases, there will be a copy of the materials with the exact same name and type set to Custom applied to the objects.
Note that in this case V-Ray is not involved with the issue and the same exact behavior will occur with any other 3rd party plugins that are disabled when saving a file. The issue has been reported to McNeel and a solution is currently being developed.
Editing materials and project files
V-Ray must be loaded during material editing
First, make sure that V-Ray is loaded as a plugin. Avoid changing the type of V-Ray placeholder material to any other type when V-Ray is not active. If this action is taken Rhino will delete the V-Ray material and create a copy based on the material simulation. Upon reopening the file V-Ray will detect that a Rhino material counterpart is missing, and it will show a message suggesting that the V-Ray scene material shall be either removed or kept. Keeping it will make a new Rhino counterpart that will look like a duplicated material in the Rhino material panel. Once the material type has been changed to Custom the V-Ray materials can no longer be fully recovered. Changing the type manually back to V-Ray or using the vrayMtlFromRhino command will perform the standard Rhino to V-Ray material conversion, however, this conversion will be lossy.
Avoid changing the V-Ray material type
Avoid changing the material type from V-Ray to Placeholder or Custom and then saving the file. This action will result in the same issue described above and the V-Ray materials would not be able to be fully recovered.
Do not delete the material without V-Ray being loaded
Delating materials when V-Ray is not installed or disabled causes the V-Ray material data to remain in the file on load but there is no Rhino material counterpart. In such a case, one of the following issues may occur: some V-Ray materials will not exist in Rhino or some of them might have a Rhino counterpart with the same name but not be connected.
Different V-Ray versions
If the file is saved on a shared drive or is transferred between different machines, make sure that all of the machines have the same V-Ray version. Since V-Ray is not backward-compatible, projects made with the newer V-Ray version may encounter issues when opened in an older V-Ray version. In addition, also make sure that Rhino is updated on all of the machines and has the same version for each computer.
Avoid using the Rhino Purge (Materials=Yes) command line
When a purge is required it is highly advisable to execute it from the V-Ray Aset Editor in order for all V-Ray assets to be handled properly. It is not advisable to use the Rhino purge command line. In cases where this is necessary, the materials should be unchecked, and the command set to "Materials = No". Using the command line with Materials = Yes may cause possible issues and further complications.
Paste and Import
When starting a project make sure to run both of the following command lines: RenderPasteConflictOption and RenderImportConflictOption And select the "UseDialogToAsk" option. This setting will grant larger control each time an object with an already existing material/material name is pasted within the project and will help prevent unwanted material duplication and data loss.
The dialogue will enable a window allowing users to choose the preferred action in such situations.
Contact Chaos Support
In case the issues reoccur despite following the workflow, please contact Chaos Support from chaos.com and log a ticket. When doing this make sure that you have saved the project by using the Project Pack tool in order to avoid losing any additional and important data that is valuable for the project investigation. If there is a previous version of the project file where the issue is NOT present, please make sure to share it as well by following the same steps.
In addition to the project files please make sure to fill in the form below, which helps us gather the important data needed for looking into the issue: https://forms.gle/9uGaJMkXrDBcsg968
We understand that this issue causes substantial inconvenience and we greatly appreciate the spared time, your patience, and your understanding.