Clay Renders in Cinema 4D with Redshift: Material Override, Exclusions and AO
A clay render replaces every material with one neutral material so lighting and form can be judged. What matters with Redshift, based on Maxon's documentation:
- Use the Material Override effect: Add it in the Render Settings and choose Custom Material to apply your own Redshift clay material. The legacy Redshift System override only gives a single lambert color.
- Exclude light-carrying materials: Glass, emissive and opacity-mapped materials break when overridden: windows block light, lamps go dark, leaf cards turn solid. Exclude those materials in the effect's Materials list.
- Add ambient occlusion when you need contact detail: Drive the clay color with Redshift's AO node, or render a full-scene AO pass as a Custom AOV.
- Keep clay and beauty in one scene: Put the override in its own Take and add the $take token to the output path, so clay and beauty files never overwrite each other.
- Rendering approvals: Clay sequences render on iRender 2x, 4x or 8x RTX 5090 or RTX 4090 servers from the same scene and takes you use for the final beauty.
A clay render replaces every material in the scene with one neutral material, so a client or lighting lead can judge form, lighting and composition without textures getting in the way. This guide shows the clay options Redshift has in Cinema 4D, how to keep glass, lights and foliage working, how to add ambient occlusion, and how to render clay and beauty from the same scene.
Checked against the Cinema 4D and Redshift documentation, November 2026.
1. How do you make a clay render in Redshift?
Use the Material Override effect in the Cinema 4D Render Settings with a Redshift material as the clay. Redshift’s own System tab override still exists, but Maxon describes it as an outdated method that only renders one lambert color (Maxon: Redshift System settings).
Two ways to make a clay render with Redshift
Based on the Redshift System settings page in the Cinema 4D documentation.
| Method | What it does | Control | Use it for |
|---|---|---|---|
| Material Override effectRender Settings | Cinema 4D's improved override, added as an Effect in the Render Settings. Custom Material mode applies your own material to every object. | Include or exclude specific materials; use any Redshift material as the clay. | Client clay passes, takes, batch renders |
| Material Override (legacy)Redshift System tab | Renders every material as the same lambert, colored by the Diffuse Color parameter (grey by default). | Color only; Maxon describes it as an outdated method. | Quick lighting checks |
| Clay render modeRedshift RenderView | Switches the IPR between beauty and clay while you work. | Uses the System tab override settings, or the color of the Material Override effect in Clay mode. | Interactive checks during lighting |
2. How to set up a clay render with the Material Override effect (step by step)
Create one clay material, apply it through the Material Override effect, and exclude the few materials that must stay real.
Settings checklist (copy or follow line by line):
Clay material (Redshift Standard Material) Base Color ............ neutral grey Reflection ............ low weight, fairly rough Render Settings › Effect… › Material Override Mode .................. Custom Material (clay material in the field) Exclude ............... glass, liquids, emissive, opacity-mapped materials Check ................... Redshift IPR: windows, practical lights, foliage
Step 1: Build the clay material
Create a Redshift Standard Material with a neutral grey base color and a fairly rough, low reflection, so highlights still show the shape of surfaces without turning into mirrors.
Step 2: Add the Material Override effect
Open the Render Settings, click Effect and add Material Override. Set it to Custom Material and drag your clay material into the material field.
Step 3: Exclude materials that carry light
Set the mode so the listed materials are excluded, and drag glass and liquid materials, emissive materials and materials with opacity maps, such as leaves and fences, into the Materials list. Exclusions work per material, so it helps to keep these materials separate from the rest.
Step 4: Check in the RenderView
Start the Redshift IPR and look at windows, practical lights and foliage first. The rest of the scene should read as clean grey shapes with correct shadows.
Quick check: windows should still let light through, lamps should still glow and leaves should keep their cut-out shapes; if not, the material is missing from the exclusion list.
The figure shows why step 3 matters.
When the glass material is overridden, the window becomes a solid grey panel, so sunlight and dome light stop at the wall and the room renders dark. An overridden emissive material stops emitting, and an opacity-mapped leaf card renders as a full rectangle with a rectangular shadow. Excluding those three kinds of material keeps the lighting of the shot intact while everything else turns to clay.
3. How to add ambient occlusion to a clay render
Redshift’s AO node darkens occluded areas such as corners and contact points (Maxon: AO node). Maxon notes that with global illumination as the norm, AO is mainly used for extra contrast in occluded areas or as a mask, which is exactly what a clay pass often needs.
- Inside the clay material: connect the AO node to the base color. Its Bright and Dark colors set the clay tone and the crevice tone; Samples, Spread, Falloff and Max Distance control smoothness, spread and reach.
- As a separate pass: for a full-scene AO layer to multiply in compositing, Maxon recommends a Custom AOV rather than the AO node.
- Noise: AO is multi-sampled; if it drives a high-contrast effect, raise its Samples.
4. How to render clay and beauty from one scene with Takes
Keep the Main Take for the final beauty and create a child Take that enables the Material Override effect. Add the $take token to the output file name so each take writes its own files, then render the takes you need from the Take Manager. One scene file stays the single source for lighting, cameras and animation, and the clay version can never overwrite the beauty.
5. Where should you render clay approvals: SaaS or IaaS farm?
Clay frames are usually much lighter than the beauty, so they suit any farm. A SaaS render farm works well when the takes are set and you only need frames back. An IaaS render farm such as iRender suits review rounds where you change exclusions or the clay material between versions, because you open the same Cinema 4D scene, adjust it in the RenderView, and render clay and beauty takes on the same machine.
These videos show Cinema 4D and Redshift jobs on iRender multi-GPU servers.
On iRender you rent a whole server with 2x, 4x or 8x RTX 5090 or RTX 4090 GPUs, with Cinema 4D and Redshift pre-installed; Prime members get activated Cinema 4D and Redshift licenses. Related guides: Redshift light groups and MoGraph in Redshift. Real render times are in our Redshift benchmark, and plans are on the Cinema 4D Redshift render farm page.
6. Redshift Clay Render FAQ
How do I make a clay render with Redshift in Cinema 4D?
Open the Render Settings, add the Material Override effect, set it to Custom Material and drag in a neutral Redshift material. Every object then renders with that material. For quick checks you can also switch the Redshift RenderView to its clay render mode.
Why does my clay render have a dark interior or solid windows?
The override also replaces the glass material, so windows become opaque and block the sun and dome light. Exclude the glass material in the Material Override effect so it keeps its transmission.
How do I keep lights working in a clay render?
Emissive materials stop emitting when they are overridden. Exclude the emissive materials, or use real Redshift light objects, which are not materials and keep lighting the scene.
How do I add ambient occlusion to a clay material in Redshift?
Connect a Redshift AO node to the clay material’s color and set its bright and dark colors, samples, spread and max distance. For a full-scene AO pass for compositing, Maxon recommends a Custom AOV instead.
Can I use the legacy Redshift material override for client clay passes?
You can, but it only renders a single lambert color and Maxon describes it as an outdated method. The Material Override effect in the Render Settings accepts any Redshift material and supports include and exclude lists.
How do I render clay and beauty versions without overwriting files?
Create a Take that enables the Material Override effect and use the $take token in the output path. Each take then writes to its own file name.
