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VRay for 3ds Max Manual
Object and Light Settings
In addition to the settings in the Render 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 normal 3ds Max object properties page. V-Ray
also defines some additional properties which can be accessed by pressing
the Object settings or
Light settings button in the
System roll-out.
V-Ray supports per object control of motion blur, indirect illumination
and shadow/matte properties. On the left is a list of all objects in the
scene and on the right are the properties. You can select multiple objects.
There is also a list of MAX selection sets to make the interface more
convenient and efficient.
![[Object settings dialog]](vray_for_3ds_max_manual/object_and_light_settings/object_settings.png) Object
properties
Use default moblur samples - when this
checkbox is selected, the Geometry Samples
value will be taken from the global
Motion blur roll-out. When this is off,
the number of geometry samples is taken from the
Motion blur samples parameter below.
Motion blur samples - here you can set the
number of geometry samples for the selected objects, if
Use default moblur samples is
off.
Generate GI - this setting controls
whether the object(s) will generate indirect illumination. You can supply a
multiplier for the generated indirect illumination.
Receive GI - this setting controls
whether the object(s) will receive indirect illumination. You can supply a
multiplier for the received indirect illumination.
Generate caustics - when this setting is
checked the selected objects will refract the light coming from light
sources that are caustics generators, so that caustics are produced. Note
that in order to generate caustics an object must have a reflective or
refractive material.
Receive caustics - when this setting is
checked the selected objects will become caustic receivers. When light is
refracted by objects that generate caustics the resulting caustics will be
only visible when they are projected on caustics receivers.
Caustics multiplier - this value is a
multiplier for the caustics generated by the selected object(s). Note that
this value has no effect unless Generate caustics
is checked.
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 will not be blended. This can be useful to
prevent light leaks between objects of vastly different illumination.
Visible to GI - when this is
off, the object will be considered perfectly
transparent to GI rays.
Visible in reflections - when this is
off, the object will appear perfectly transparent
to reflection rays.
Visible in refractions - when this is
off, the object will appear perfectly transparent
to refraction rays.
Matte properties
V-Ray does not completely support the Matte/Shadow material of 3ds Max.
However, V-Ray has its own matte system. You can control matte properties
either on an object level through the Object settings dialog, or on a
material level through the special
VRayMtlWrapper material.
Matte object - checking this option will
turn the object into a matte object. This means that the object will not be
directly visible in the scene; instead, the background color will be shown
in its place. However, the object will appear normally in
reflections/refractions and will generate indirect illumination based on its
actual material.
Alpha contribution - this allows you to
control how the object will appear 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 will
appear normally in the alpha channel. A value of 0.0 means that the object
will not be present in the alpha channel at all. A value of -1.0 will invert
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.
Direct light
Shadows - this will make the matte object
receive shadows.
Affect alpha - this will cause the shadows
to affect the alpha of the object.
Color - the color of the shadows.
Brightness - the brightness of the
shadows.
Reflection/refraction/GI
Reflection amount - if the material of the
object is a reflective V-Ray material, this controls how much of the
reflection will be 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 will be visible on the matte object.
GI amount - this controls how much of the
indirect illumination received by the object will be visible on the matte.
No GI on other mattes - this will cause
the object to appear as a matte object in reflections, refractions, GI etc
for other matte objects. Note that if this is ON, refractions for the matte
object might not be calculated (the object will appear a matte object to
itself and will not be able to "see" the refractions on the other side).
![[Light settings dialog]](vray_for_3ds_max_manual/object_and_light_settings/light_settings.png) In
this dialog you can specify properties of the lights in the scene with
regards to caustics and global photon mapping. On the left is a list of
light sources in the scenes and on the right are the light settings. You can
select multiple light sources. There is also a list of 3ds Max selection
sets to make the interface more convenient and efficient.
Generate caustics - when this setting is
checked, V-Ray will generate caustic photons for the selected light sources.
Note that to obtain the caustics effect you must set the appropriate value
for the Caustics multiplier below as well as
put some objects that generate caustics in the scene.
Caustic subdivs - this option controls the
amount of photons that V-Ray will trace to estimate caustics. Large numbers
slow down the calculation of the caustics photon map and may take more
memory.
Caustics multiplier - this value is a
multiplier for the generated caustics by the selected object. Note that this
multiplier is cumulative - it does not override the multiplier in the
Caustics render roll-out section. The
multiplier has no effect unless Generate caustics
is checked.
Generate diffuse - when this is checked,
V-Ray will generate diffuse illumination photons for the selected light
sources. See the
Global photon map section for more details.
Diffuse subdivs - controls the number of
diffuse photons traced for the selected light(s). Larger values mean a more
precise photon map, but will take more time and memory.
Diffuse multiplier - a multiplier for the
diffuse photons.
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