VRayProxy Overview
VRayProxy allows you to import geometry from an external mesh file which can be either VRayMesh or Alembic file. The geometry is not present in the scene during modeling and does not consume any resources. This allows the rendering of scenes with very heavy geometry. At render time, V-Ray will load the actual geometry (instead of the preview) as needed. The .vrmesh File Format
Meshes are exported to a special .vrmesh (V-Ray Mesh) file format. It contains all the geometric information for a mesh - vertices and face topology as well as texture channels, face material IDs, smoothing groups, normals - in short, everything that is needed to render the mesh. In addition, the mesh is preprocessed and subdivided into chunks for easier access. The file also contains a simplified version of the mesh used for preview purposes in the viewports. More information about the .vrmesh file format is available in the documentation of the V-Ray SDK. It is important to realize that the mesh is in a "ready to render" format. No further modifications to the mesh are expected. You can't apply modifiers to the mesh, or animate it in any way except if you animate the position/orientation of the proxy object. There is no way to recover the original mesh from a .vrmesh file (this can be done in principle, but is currently not supported). Therefore, if you plan on doing modifications to the mesh, you should keep it in a Softimage file (which may be different from the file that gets rendered in the end). Exporting a Mesh to a File
Before importing a mesh through a VRayProxy object, you need to create the mesh file first. This can be done either from the Softimage interface (the ExportToVRayMeshOptions menu dialog) or through the script command ExportVRayMesh (for more details see Custom Commands). ExportToVRayMeshOptionsTo export a .vrmesh file from the user interface, open the scene where you have the object(s) you'd like to export as VRayProxy objects, select the object(s) and from the File menu choose Export > Export to (.vrmesh). This will bring out the create proxy dialog: Folder - this is the directory where the mesh file will be created. File Name - this is the name of the .vrmesh file, if you have selected the Export all selected objects in a single file option. You don't need to specify a path - the Path folder will be used. Export all selected objects in a single file - this option will take all selected objects and will merge them into one mesh file. This option also stores the transformations of the selected objects. When you import the file with a proxy object, it must be centered at the origin, if you want the objects to be in the same place. Export each selected object in a separate file - this option will create one file for each selected object. The name of each file is derived from the name of the corresponding Softimage node. The transformation of an object is not included in its mesh file unless specified via Include node transformation option, and the corresponding proxy must have the same transformation as the original object, if it is to appear in the same place. Note that you can use this option even with a single object, which will cause the object pivot to be preserved in the exported .vrmesh file. Include node transformation - Specifies whether geometry objects transformations should be written into the vrmesh file(s). Group faces in output - this option allows you to group multiple faces by assigning them an unique material ID. This is useful during shading when different parts of the proxy need to be shaded differently. - by assigned material - when this option is selected, faces that have the same material will be assigned the same Material ID
- by map to existing clusters - when the faces in the geometry have been previously divided into clusters, this options assigns the same material ID to the faces in each cluster regardless of the material assigned to individual faces.
Overwrite existing vrmesh file - when checked V-Ray will automatically overwrite any existing vrmesh files. |