Reference Cinema 4D Cinema 4D Visualize, Broadcast, Studio Advanced Render Shadow Catcher
Function available in CINEMA 4D Studio
Shadow Catcher

Shadow Catcher Assign Illumination


Generate GI

Deactivate this setting if a given material should not have an effect on other objects.

Strength [0..10000%]

Use this setting to define how strong a given material will emit. The default value is 100% and values up to 10000% can be entered.

Saturation [0..1000%]

From left to right: Increasing saturation values.

Use this setting to define the level of saturation of the light radiated or reflected from the material. This lets you accurately adjust the "color bleeding" for that material.

Receive GI

Deactivate this option if a given material should not receive brightness or color from other objects.

Strength [0..10000%]

When active you can define to what degree a given material will receive color and brightness of other materials.

Saturation [0..1000%]

Use this setting to fine-tune the saturation of textures used for GI. Contrary to the previously described Saturation, this setting affects only the receiving of GI, not the radiation of it.

An area of high saturation is in the center.

GI Area Light

If this option is enabled, the way in which a (luminous) object is included in the GI calculation will be optimized. This option should be enabled if the object serves as an Area light. Additional information can be found under GI Portals and Polygon Lights: Function and Placement and Sampling.

Note that, despite its name, this function has a positive effect even on matte reflections.

GI Portal

Activating this option will define the object to which it is assigned as a GI Portal (make sure you also activate the Transparency channel).

GI Portals are usually single-polygon surfaces (e.g., primitive Plane) that are placed where light passes through relatively narrow openings. The direction in which the Normals show is irrelevant. Further details can be found here.

If you do not want to make corresponding changes to the light-reflecting object itself, you can influence the light passing through the GI Portal by changing the Color or Brightness settings in the Transparency channel.

The following applies for ProRender: Polygon lights (objects with luminous materials) do not have to be defined as GI Area Lights. This happens automatically. GI portals (samples are used in regions in which light, for example from HDRI skies, is cast into a room) must on the other hand still be defined. The Normal orientation is important - the Normals must point in the direction of the room’s interior.

Generate Caustics

Enable this option to activate Photon caustics generation for the active material. Make sure that either the Transparency (for caustics that result from light breaking through water in a glass) or Reflection (for caustics resulting from light reflecting from a curved object) material channels is active.

Only the Generate parameter is relevant when using volume caustics.

Strength [0..10000%]

Use the input box to set the strength of the effect.

Receive Caustics

This enables/disables the reception of surface Photon caustics for the material.

Strength [0..10000%]

Use the input box to set the strength of the effect.

Radius [0..+∞m]

This specifies how close photons must be to one another in order to be interpolated. Higher values tend to produce better results but they also take longer to render.

Radius = 1; individual photons can be seen as points of light because they are not interpolated together.

Radius = 10.

Radius = 100.

Larger values would only make the Photon Caustics appear more blurred.

If the defined value is too small, individual photons will become visible. This might make for an interesting visual effect but is not suited for realistic renderings. Larger values will combine and interpolate photons accordingly, which produces a realistic caustics effect.

Samples [1..10000]

This defines the maximum number of photons within the Radius that are used to calculate the effect. For example, if you enter a value of 100, up to 100 photons will be evaluated — any photons in excess of this number are ignored. Samples and Radius both affect the quality of the effect.

To summarize: more samples per radius means a more accurate image. Increasing the Radius means more blur but a longer render time also.