Redshift Proxy guide for speeding up interior scenes (Cinema 4D / Houdini)

In interior and exterior visualizations containing dense vegetation, furniture libraries, or crowded scenes, the biggest performance bottleneck is usually not a single object but repetitive geometry with thousands of polygons. Redshift's Proxy system keeps such heavy data in an optimized format on disk instead of loading it directly into the scene, pulling it into memory only when a ray hits the object's bounding box. This guide, based on Maxon's official Redshift documentation, explains the steps for exporting proxies, placing them in a scene, and using them in the render pipeline.

What is a proxy, and why use one?

A Redshift Proxy is a pre-exported geometry file (with the .rs extension) that behaves like an independent Redshift scene in its own right. According to Maxon's documentation, the main advantages of using proxies are:

• There is almost no time cost during scene transfer; the cost of extracting large geometry is paid only once, at export time.

• Proxy files are stored in an optimized format on disk, so the renderer can use the data directly without extra processing or memory overhead.

• Animated and deforming meshes, hair, strands, instances, volume containers, lights, and the materials applied to them are all supported.

• Proxy files are DCC-independent; a file exported from Maya can be imported as a proxy in Houdini, or vice versa.

On the other hand, once exported, the geometry inside a proxy cannot be deformed or altered except for tessellation settings; only the position, rotation, and scale of the entire proxy as a rigid object can be animated, not the position of its components.

Steps for exporting a proxy in Cinema 4D

1. Open the export window via File › Export › Redshift Proxy (*.rs).

2. In the Export field, choose whether to export the entire scene or only selected objects.

3. Leave the Lights option enabled if you want to include lights.

4. If you plan to apply tessellation or displacement after placing the proxy in the scene, enable Polygon Connectivity; this option increases file size, so it should only be used when necessary.

5. Pay attention to unit conversion in the Scale field; according to the documentation, working in centimeter units but exporting in millimeter units brings the object in as a proxy that is 10 times larger.

For those who want to replace exported materials with scene materials, there are three options: Proxy File (the materials in the file are used as-is), Object (the scene material assigned to the placement mesh replaces everything), and Scene (Match by name and prefix) (individual material replacement based on name and prefix matching).

Which setting changes what?

If you're planning to use instancing, the documentation explicitly states:

Adaptive tessellation instancing sırasında kullanılamaz, yalnızca fixed (sabit) tessellation desteklenir.

For an object that needs multiple copies (such as a repeating chair or plant), creating a single proxy and placing multiple instances of it in the scene is far more efficient in terms of memory and performance.

Preview and instancing in Houdini

Redshift's Houdini plugin supports exporting proxy files via the ROP node and instancing using the instancefile point attribute. If this attribute is present, the object is output as an instancer loaded by file path at render time, and can be configured via Redshift Instances or Redshift Point Clouds. However, material override functionality is currently not supported when working with instancefile.

Rendering from the command line (redshiftCmdLine)

For studios that want to render a scene without opening any application, the Redshift CmdLine tool can be used. First, the scene is exported as a proxy including camera, lights, materials, geometry, animation, and AOV settings:

C:\Program Files\Maxon Redshift 20XX\bin\redshiftCmdLine.exe C:\demo\proxy\RS_Proxy_Demo.rs -oip C:\demo\proxy\images

To change render options, a text file can be prepared and passed with the -oro argument:

redshiftCmdLine myscene.rs -oro myrenderoptionoverrides.txt

How do these settings affect archviz workflow?

In interior visualization, furniture, plant, and accessory libraries usually constitute the heaviest polygon load. Exporting these objects as proxies shortens scene opening/saving times and keeps the viewport fluid; the difference is especially noticeable in scenes with many repeating objects (forests, crowded furniture layouts). For offices sharing files within a team, the DCC-independence of proxies means a plant library prepared in Maya can be used in a 3ds Max or Houdini scene; however, it should be kept in mind that embedded shaders may not work correctly in a different DCC.

Common mistakes

• Redshift automatically deletes attributes like UV or vertex color at export time if they aren't used by the assigned material, to prevent file bloat; if a material override is planned later, care must be taken to assign a shader to the proxy that uses the relevant attribute.

• Motion blur settings (such as frame duration) cannot be changed after export; to change the motion blur setting of an animated proxy, re-exporting is required.

• The original Maya, 3ds Max, or Softimage mesh data cannot be retrieved back from the proxy file; keeping the source files is recommended.