This page provides information on the V-Ray Object Properties.
In addition to the settings in the Render Settings dialog, which are global for the scene, you can set different render settings on a per-object basis. Some of those properties (primary and secondary visibility, visibility to camera etc) are accessible through the additional V-Ray Object Properties.
||Select object(s)|| > V-Ray Shelf > Right-click Object Properties
Object ID – Specifies an ID for the object. This is used by the MultiMatte render element which creates selection masks based on Object IDs.
Generated GI Mult. – A multiplier that controls how much indirect illumination the object generates.
Received GI Mult. – A multiplier that controls how much indirect illumination the object receives.
Generated Caustics Mult. – A multiplier that controls how much caustics the object generates. Note that in order to generate caustics, an object must have a reflective or refractive material.
Received Caustics Mult. – A multiplier that controls how much caustics the object receives. When light is refracted by objects that generate caustics, the resulting caustics are only visible when they are projected on caustics receivers.
Subdivs Mult. – Specifies a multiplier for the subdivisions of all secondary ray tracing done for the particular surface.
Use Irradiance Map – When enabled, the irradiance map is used to approximate diffuse indirect illumination for the object. If disabled, brute force GI is used. You can use this for objects in the scene which have small details and are not approximated very well by the irradiance map.
Alpha contribution – Controls how the object appears in the alpha channel. Note that this parameter does not require the object to be a matte object - this parameter has an effect on all objects. A value of 1.0 means that the object appears normally in the alpha channel. A value of 0.0 means that the object is not present in the alpha channel at all. A value of -1.0 inverts the alpha of the object. Note that turning an object into a matte object does not change its appearance in the alpha channel. You need to explicitly change its alpha contribution. This can be mapped by a texture.
Generate Render Elements – This option can include or exclude the selected object(s) from certain Render Elements on a per-object basis. When disabled, the selected object's information is excluded from the following Render Elements:
Matte Surface – Enabling this option turns the object into a matte object. This means that the object is not directly visible in the scene; instead, the background color is shown in its place. However, the object appears normally in reflections/refractions and generates indirect illumination based on its actual material.
Shadows – When enabled, the matte object receives shadows.
Affect Alpha – When enabled, makes shadows affect the alpha contribution of the matte surface. Areas in perfect shadow produce white alpha, while completely unoccluded areas produce black alpha. Note that GI shadows (from skylight) are also computed, however GI shadows on matte objects are not supported by the light cache GI engine, when used as primary engine. You can safely use it with matte surfaces as secondary engines.
Shadow Tint – Specifies the color of the shadows.
Shadow Brightness – An optional brightness parameter for the shadows on the matte surface. A value of 0.0 makes the shadows completely invisible, while a value of 1.0 shows the full shadows.
Reflection Amount – If the material of the object is a reflective V-Ray material, this controls how much of the reflection is visible on the matte object.
Refraction Amount – If the material of the object is a refractive V-Ray material, this controls how much of the refraction is visible on the matte object.
GI Amount – Controls how much of the indirect illumination received by the object is visible on the matte.
No GI On Other Mattes – When enabled, causes the object to appear as a matte object in reflections, refractions, GI, etc. for other matte objects. Note that if this is enabled, refractions for the matte object might not be calculated. (The object appears as a matte object to itself and is not able to "see" the refractions on the other side.)
Matte For Secondary Rays – Normally the base material is used when an object with a V-Ray MtlWrapper is seen through reflections/refractions. If Without Projection Mapping is selected, the material acts as a matte for all secondary rays (reflections, refractions). If With Projection Mapping is selected, the material will perform automatic projection mapping of the environment map on the matte geometry.
GI surface ID – This number can be used to prevent the blending of Light Cache samples across different surfaces. If two objects have different GI surface IDs, the light cache samples of the two objects are not blended. This can be useful for preventing light leaks between objects of vastly different illumination.
Trace Depth – Specifies a maximum reflection depth.
When creating a matte object with V-Ray Object Properties and using the V-Ray CUDA engine, please note the following:
- Alpha Contribution should be set to -1.0;
- The Matte Surface, Affect Alpha and Shadows options should be enabled.