V-Ray Proxy Guide: Mesh, Scene, and Chaos Cosmos

Learn how dynamic geometry, V-Ray proxies, and Chaos Cosmos work together to improve your workflow and enrich your scene. Adding complex details to 3D scenes often results in high polygon counts, which is the most common reason for slow viewport navigation and freezing issues. Dynamic geometry offers the best solution to keep your workflow smooth without sacrificing detail.

Key takeaways:

• Dynamic geometry helps manage heavy scenes by only keeping rendered pieces in RAM, preventing viewport freezing.

• V-Ray Proxy Mesh imports geometry at render time, allowing complex models without slowing navigation.

• Proxy Scene files include geometry, materials, and lights, making them useful for sharing complete sets across projects.

• Chaos Cosmos assets offer high detail with different levels of detail for efficient rendering in V-Ray Vision.

• Choose between Proxy Mesh and Proxy Scene based on project needs for material control or finalized asset sharing.

Table of Contents:

• What is dynamic geometry?

• What is a V-Ray Proxy Mesh?

• Proxy parameters and settings

• What is a Proxy Scene?

• Animation and dynamics with V-Ray Proxies

• Adding Chaos Cosmos assets

• V-Ray Proxy Mesh vs Proxy Scene — similarities, differences, and benefits

• Which should you use? A quick decision guide

• FAQs

When creating an interior or exterior scene, 3D artists often add a lot of different geometry and details to make it appear more interesting and realistic. More often than not, this results in a heavy scene with a high amount of polygons, which is the most common reason for slow navigation in the viewport and freezing issues.

In these situations, dynamic geometry can be the best solution. In this article, we explore its use in V-Ray for SketchUp, Rhino, and Revit. We also look at how V-Ray’s proxies tie into the process, and how Chaos Cosmos adds an extra layer of flexibility and ease of use in creating rich, realistic scenes.

© Chaos 3D Team

What is dynamic geometry?

Dynamic geometry is a specialized approach to handling heavy geometry, in which only the pieces currently being rendered are kept in RAM. It is a capsulated file that does not allow you to modify the geometry directly, making it an ideal solution for complex models. It displays a low-poly representation in the viewport to avoid freezing issues, but renders the high-poly version in the final output.

Before you get started with dynamic geometry, you need to understand proxies. In V-Ray, you have two proxy options: V-Ray Proxy Mesh and Proxy Scene.

Why should you use dynamic geometry in your scenes?

Dynamic geometry not only allows you to handle heavy geometry, but it also enables you to save it in different states or set it for use in multiple projects.

Another common situation where dynamic geometry can be very helpful is when you are working on complex projects that require splitting tasks among different people, as well as reusing assets across multiple projects. Having a library of assets already set up and ready to render can significantly speed up and improve your workflow.

What is a V-Ray Proxy Mesh?

A V-Ray Proxy imports geometry from an external mesh at render time only. The geometry is not present in the scene, and it only takes up the necessary resources for its preview. This allows the rendering of scenes with many millions of triangles.

Some important considerations:

• Proxy meshes are used to display high-polygon geometries that load only during rendering time. Heavy geometry is represented in the scene with a low-poly preview, but rendered as the high-poly version. You can also attach displacement maps or modifiers to the proxy object for advanced rendering effects.
• Once the original geometry is converted to a proxy mesh, it becomes a “ready to render” format. No further modifications to the mesh can be made.
  
  

‼️ Important: Adding a modifier to a VRayProxy object causes it to lose its memory-saving properties, and it is then treated as a regular mesh in the scene. Always make any necessary modifications to the original geometry before exporting to .vrmesh, not to the proxy object itself.

• Before converting the geometry to Proxy, you need to assign materials so the corresponding slots are available for replacement later. Material names are used to create these slots for later assignment. V-Ray Proxy objects do not store materials; they only save geometry, so if the materials are deleted from the scene, the proxy will not display them correctly.
• The V-Ray Proxy Mesh can be loaded in other platforms and rendered, for example, by V-Ray for 3ds Max, V-Ray for Rhino, V-Ray for SketchUp, V-Ray for Revit, or V-Ray for Maya. When importing or managing proxies, you can adjust or override attributes of existing proxy files, such as UVs or materials, without re-exporting the entire scene.

Supported file formats: .vrmesh and .abc

• V-Ray Proxy supports two file formats: the native .vrmesh format and Alembic (.abc)
• .vrmesh contains: Vertices, face topology, texture channels, face material IDs, smoothing groups, normals, preprocessed chunks for faster access, and a simplified preview mesh
• .abc (Alembic) is an open format commonly used for animated geometry, character caches, particles, and hair — supported directly without conversion
• Animated proxies can be stored as a single file or as a sequence of files (one per frame)
• Both formats are cross-platform: load in 3ds Max, Maya, SketchUp, Rhino, Revit, and more

Object Hierarchy: visibility and material overrides

• When a proxy file contains multiple objects, the Object Hierarchy panel displays the full file structure as a tree view
• Individual objects within the proxy can be selected and given visibility overrides (force visible, force invisible, or inherit from parent)
• Material overrides can be applied per object: Replace the original material with any scene material without modifying the proxy file
• Advanced wildcard rules allow applying overrides to multiple objects at once using name patterns (e.g., tree applies to all objects containing "tree" in their name)
• This makes it possible to use a single proxy file in multiple contexts with different materials or visibility setups without re-exporting.

© Chaos 3D Team

When to use V-Ray Proxy Mesh

V-Ray Proxy Meshes are ideal when adding specific models, such as furniture, decorations, or plants, where you need to maintain control and customization over the materials (i.e., change materials or modify their look).

💡 Use case: Import trees as proxies and scatter them around a building. Using proxies also allows you to build a library of assets that can be shared with anyone. Store your models in a custom library folder locally or on a drive or a server.

Creating a V-Ray Proxy Mesh

Follow the steps below to create a Proxy Mesh in your current project.

1. Prepare the geometry - assign all the needed materials in order to create the corresponding material slots for the Proxy. Note: Material overrides or modifications can be added before exporting, or by re-importing the mesh after adjustments to enhance workflow flexibility.
2. You can export a mesh through the V-Ray Object Toolbar (V-Ray for SketchUp and Rhino) or through the Extensions menu (V-Ray for SketchUp).
3. If you are using V-Ray for SketchUp, to create a proxy through the V-Ray Object Toolbar, select the group or component you want to convert.
4. Choose Proxy Mesh (.vrmesh) in the Mode menu.
5. Choose the method for generating the proxy preview:
   Face skipping: The fastest preview method.
   Refined clustering: Slightly slower, but generates a more precise preview mesh.
   Vertex clustering: This method is fast and generates a fairly precise preview mesh.
6. Specify the number of faces in the viewport preview of the proxy if needed (the higher the number of faces, the more detailed the preview). Changing this parameter is not mandatory; you can leave the value at its default.
7. Export the .vrmesh file to the specified folder. The newly created proxy will retain its materials.
8. You can also open a custom folder in the Asset Editor and drag and drop the newly created proxy into the custom folder location.

Importing a V-Ray Proxy Mesh

Follow the steps below to import a Proxy Mesh into your current project.

1. Click the Import V-Ray Proxy button and choose a .vrmesh file from your computer by specifying the correct file path to the proxy mesh. Once loaded into the scene, you will need to reapply materials through the Material Editor. The imported proxy mesh can be found in the specified folder or asset library after import.
2. You can also save it as .vrmat, or open a custom folder in the Asset Editor and drag and drop the imported proxy with the assigned materials into that folder.
3. When a proxy asset is saved as a .vrmat file, both its source file (.vrmesh or .abc) and its referenced material asset files (texture maps) are saved in a subfolder called Maps. You can also save different materials in the same proxy mesh. This will let you create material variations and switch between them.
4. In case the imported V-Ray Proxy Mesh contains an animated object, you can turn on or off the animation as well as control some of its playback parameters.

Proxy parameters and settings

Configuring proxy parameters is essential to optimize scene performance, manage memory usage, and ensure smooth rendering.

• Mesh file parameter: Points to the external .vrmesh or .abc file where your geometry is stored. It efficiently holds all necessary data (vertices, topology, texture channels, etc.) so your proxy renders accurately without bogging down the scene.
• Preview override: Controls how the proxy appears while you work. Choose between a bounding box, point cloud, or simplified mesh to keep viewport navigation fast and responsive.
• Proxy Params: Offers further display control, letting you use a bounding box for maximum speed or preview from file for more viewport detail.
• LOD Scale: Helps balance detail and performance in complex scenes by determining the maximum pixel length an edge can span before subdivision.
• Expand # to frame number: When using animated proxies, adding a "#" to your file name represents frame numbers, making it easy to manage animation sequences directly from the proxy object.

These settings behave consistently across platforms like 3ds Max, Maya, Rhino, and SketchUp. Taking the time to fine-tune them will help you avoid viewport slowdowns, reduce memory consumption, and keep your renders fast.

© Chaos 3D Team

What is a Proxy Scene?

A Proxy Scene is a file format that imports geometry from an external mesh solely at render time. While it works similarly to other proxies, there are a few distinct differences between a Proxy Scene and a standard V-Ray Proxy Mesh.

• Export flexibility: You can export a whole scene or just selected parts of it to use across multiple projects.
• Included data: The file contains geometry, materials, animation, and lights, and you can switch off the animations and lights when importing the file into another project.
• Asset customisation: Some workflows allow you to modify the geometry or materials of your imported assets.
• Advanced control: In complex proxy or Alembic workflows, you can apply rules to manage object visibility or material assignments, using structured patterns and overrides to control rendering attributes efficiently.
• Cross-platform compatibility: You can load and render a Proxy Scene in other platforms, such as V-Ray for 3ds Max, V-Ray for Rhino, V-Ray for SketchUp, V-Ray for Revit, or V-Ray for Maya.

When to use Proxy Scene

A Proxy Scene is best used when you need to prepare and share ready-to-use, complete sets of geometry that do not require any additional material modifications.

• Share complete sets: Ideal for exporting entire collections, such as living room furniture or environmental sets like street furniture and trees.
• Split the workload: It is incredibly useful for dividing complex projects between different people or departments.

💡 Use case: Imagine two artists working on a single project: one is modeling the building, and the other is building the environment. Exporting the environment as a Proxy Scene allows the first artist to bring it directly into the building scene without having to set up the environment materials from scratch.

Animating with Proxy Scene

• Proxy Scene files can contain animated geometry
• Playback type options: Loop (repeats), Once (plays once and stops), Ping-pong (plays forward then backwards)
• Playback speed: A multiplier — 1.0 is normal speed, 2.0 is double speed, 0.5 is half speed, negative values play backwards
• Offset: delays the start of the animation by a given number of frames — useful when multiple proxy animations need to be desynchronised to avoid identical timing across instances
• Animation Start and animation Length: control which portion of the animation is played

Importing a V-Ray Proxy Scene

Follow the steps below to import a V-Ray Proxy Scene in your current project.

1. Click on the Import Proxy or V-Ray Scene button.
2. Choose a .vrscene file from your computer. Note: Keep in mind that when the V-Ray scene is imported this way, the file is capsulated and you cannot modify it.

💡 Pro tip: SketchUp internally operates in inches. When importing a Proxy Scene, dimensions are always set at a scale of 1 inch per original unit. If the .vrscene was created in a metric application (3ds Max, Maya, Rhino), scale adjustments may be needed after import to match real-world dimensions.

If you are using V-Ray for SketchUp, there is a second way to import a .vrscene file, which you can use in case you wish to be able to modify the Proxy Scene. In SketchUp, navigate to File > Import and select your V-Ray Scene file.

Note: Importing the V-Ray Scene this way allows you to edit the geometry and change materials.

Exporting a V-Ray Proxy Scene

Depending on what you would like to export, the whole scene or only parts of it, there are two approaches to take.

1. Export part of the scene: Select a group or a component you want to export and export through the V-Ray Objects Toolbar. In the Mode menu, select Proxy Scene (.vrscene)
2. Export the whole scene: Open the Asset Editor, left-click on the arrow in the lower left corner of the render button, and press the Export V-Ray Scene File button

Replace Object with Proxy

• When enabled during export, the source geometry in the scene is automatically replaced with the proxy version. Material assignments are preserved. Useful for keeping the scene clean without manual deletion.

Strip Paths

• Converts all absolute file paths in the .vrscene to relative paths. Essential when transferring a .vrscene to another machine — ensures all referenced assets (textures, .vrmesh files) can still be found as long as they are in the same folder as the .vrscene file.

Cameras and render settings are not imported from .vrscene files, even if they are present in the file. Only geometry, materials, and lights are brought in.

© Chaos 3D Team

Animation and dynamics with V-Ray Proxies

Animation and dynamics with V-Ray Proxies

Both .vrmesh and .abc proxy files can store animation. Once imported, the following playback controls are available:

• Loop / Play once / Ping-pong / Still: controls how the animation repeats
• Offset (frames): Shifts the animation start forward or backward, useful for staggering multiple proxy objects
• Speed: Playback rate multiplier; negative values play the animation in reverse

Hair and particles

• Tessellate hair: enables dynamic tessellation at render time; use Edge length to control detail level
• Particle Render Mode: renders particles as spheres or points

Alembic Layers

When the proxy is an .abc file, additional layer files can be attached on top of the base proxy to add, override, or replace properties — for example adding UV mapping to geometry exported without it. Layers can be enabled, disabled, or deleted from the stack individually.

Proxy Mesh visibility

When a single .vrmesh or .abc file contains multiple objects, use the Include or Exclude list to control which objects are visible in the render — by object name or object ID.

Adding Chaos Cosmos assets

Chaos Cosmos makes it easy to populate your scene with different kinds of assets. Because imported Cosmos assets are already capsulated files that render as high-poly geometry, you do not need to convert them to a proxy or Proxy Scene.

Unlike a standard V-Ray Proxy Mesh , Cosmos assets come with built-in levels of detail (LOD) linked directly to V-Ray Vision:

• V-Ray for SketchUp always loads the highest LOD when rendering.
• V-Ray Vision defaults to the second-highest LOD (either medium or low, depending on the asset).
• Assets placed far in the background automatically switch to their lowest LOD for efficiency.

Modifying Cosmos materials

Keeping the default Cosmos asset is great if you use V-Ray Vision and do not intend to modify the materials. However, if you need to edit the materials, you must convert the asset into a V-Ray Proxy.

To do this, click the merge button in the Asset Editor. This converts the Cosmos asset to a standard proxy mesh, populating your scene with editable materials and lights.

‼️ Important: The merging process is irreversible. It automatically switches the asset to High LOD and breaks the link to Cosmos. As a result, the special LOD assignments and lower LOD versions used by V-Ray Vision will be permanently lost.

Cosmos asset variants: Switching materials and geometry without merging

• Cosmos assets that contain variants allow switching between material and geometry variants directly in the Asset Editor, without converting to V-Ray Proxy
• Material variant: Changes the asset's material appearance
• Geometry variant: Changes both the geometry and the material
• This is a non-destructive alternative to merging: The link to Cosmos is preserved, LOD behaviour in V-Ray Vision is maintained, and the process is fully reversible
• Merging is only necessary when you need to make custom material edits that go beyond the available variants
  

© Chaos 3D Team

V-Ray Proxy Mesh vs Proxy Scene — similarities, differences, and benefits

Similarities:

• Geometry is imported from an external mesh at render time only.
• The mesh has a low poly representation in the viewport.
• Both are a capsulated format that does not allow you to modify the geometry.
• Can contain animation.

Differences:

• V-Ray Proxy Mesh keeps only material slots assigned to geometry prior to converting it to Proxy Mesh. Once it’s loaded, you need to re-assign materials.
• An exported V-Ray Proxy Scene will include all assigned materials and lights that were present in the scene.
• Alembic layers or modifications can be deleted from the stack to undo or discard changes, providing flexibility in managing imported data.
• Filtering or hierarchy management systems are updated after editing, such as pressing Enter, Tab, or clicking elsewhere, to refresh the view and apply changes.

Benefits of using V-Ray Proxy Mesh and Proxy Scene:

• Use complex models in any scene without worrying about slow navigation or viewport freezing.
• Easily create and share custom libraries of assets.
• Share whole scenes or selected parts.
• Scatter complex geometry without making the scene heavy and difficult to manage.
• Sharing and reusing assets on different platforms.

Which should you use? A quick decision guide

Whether you are adding furniture or scattering vegetation to create forests, your choice ultimately depends on your specific project needs. Use the quick decision table below to determine the best tool for your scenario:

Using Dynamic Geometry is a great way to add as much detail to your scene as needed without worrying about any viewport or navigation slowdown. From adding furniture to scattering vegetation and creating forests - it's all possible with V-Ray Proxy Mesh and Proxy Scene.

Choose which one to use depending on your current project needs. The V-Ray Proxy Mesh is a great solution when you wish to retain control over the materials, and Proxy Scene would be a more suitable option when you wish to add or share assets that have been already finalized and you do not need to adjust any shaders.

And if you use assets from Chaos Cosmos and your workflow relies heavily on using V-Ray Vision for preview, it is better to keep the assets as they are. And after you reach the stage where you need to modify the shaders, you can merge the Cosmos assets with your scene and treat them as a standard V-Ray Proxy Mesh.

FAQs

How to reduce 3ds Max file size using V-Ray proxies?

Converting heavy geometry into a V-Ray Proxy Mesh significantly reduces your overall file size. V-Ray Proxy imports geometry from an external mesh at render time only. Because the geometry is not fully present in your scene file, it only takes up the necessary resources for its preview, keeping your project lean.

V-Ray proxy vs standard geometry — what is the performance difference?

The main performance difference lies in RAM management and viewport responsiveness. Standard geometry loads all polygons simultaneously, often causing slow navigation and freezing issues. With a V-Ray proxy, heavy geometry is represented in the scene with a low-poly preview, but rendered as the high-poly version.

What is the difference between V-Ray Proxy and XRef objects?

V-Ray proxies are optimized specifically for the rendering engine, whereas XRef objects are a native 3ds Max feature for scene organization. XRefs allow you to reference entire external scenes to collaborate with other artists, but they can still be heavy for the software to process. V-Ray Proxies are stripped-down, highly efficient files designed strictly to save RAM and render extremely fast.

What are the best practices for V-Ray proxy material management?

You must assign materials before converting your geometry to a proxy to ensure the proper material slots are created. V-Ray Proxy objects do not store materials; they only save geometry. If you delete the materials from your scene, the proxy will not display correctly, meaning you must always re-apply your materials through the Material Editor after importing the proxy into a new project.

V-Ray Proxy vs Alembic vs USD — which is best for large scenes?

Your choice depends entirely on your specific pipeline and the type of data being transferred. V-Ray Proxy (.vrmesh) is heavily optimized for static, high-poly assets directly within V-Ray. Alembic (.abc) is an open format commonly used for animated geometry, character caches, particles, and hair. USD (Universal Scene Description) is the industry standard for large, collaborative pipelines where entire environments and lighting setups need to be shared non-destructively across different 3D software packages.

Are V-Ray proxies supported in V-Ray GPU rendering?

Yes, V-Ray proxies are fully supported in V-Ray GPU rendering. You can render scenes with millions of polygons using your graphics card by taking advantage of the same memory-saving techniques and external file referencing used by the CPU engine.

How do I convert OBJ, FBX, or Alembic files into V-Ray proxy format?

You can convert OBJ and FBX files by first importing them into your primary 3D application, applying the correct materials, and then exporting the geometry as a .vrmesh file. Alembic (.abc) files, however, are supported directly without conversion. V-Ray Proxy natively supports Alembic formats alongside its native .vrmesh format.