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VRay for SketchUp New Features Guide
Lights: SpotlightSpotlight:
 This is a new
V-Ray for SketchUp light type that can be used to create a spotlight. The icon
is located in the main V-Ray toolbar.
Enable Controls
On: Turns on or off the spotlight.
Shadows: Turn on or off the spotlight shadows.
Affect Diffuse: This determines whether the light is affecting the
diffuse properties of the materials.
Affect Specular: This determines whether the light is affecting the
specular of the materials.
Area Specular: When this option is Off the particular light will be
rendered as a point light in the specular reflections.
Intensity
Color: This parameter determines the color of the light.
Intensity: Determines the intensity of the light.
Units: Allows choosing the light units. The different units are:
Default (scalar): The color and multiplier directly determine the
visible color of the light without any conversion. The light surface will appear
with the given color in the final image when seen directly by the camera
(assuming there is no color mapping involved).
Lumious Power (lm): Total emitted visible light power measured in lumens.
When this setting is used, the intensity of the light will not depend on its
size. A typical 100W electric bulb emits about 1500 lumens of light.
Luminance (lm/m^2/sr): Visible light surface power measured in lumens per
square meter per steradian. When this setting is used, the intensity of the
light depends on its size.
Radiant Power (W): Total emitted visible light power measured in watts.
When using this setting, the intensity of the light does not depend on its size.
Keep in mind that this is not the same as the electric power consumed by a light
bulb, for example. A typical 100W light bulb only emits between 2 and 3 watts of
visible light.
Radiance (W/m²/sr): Visible light surface power measured in watts per
square meter per steradian. When this setting is used, the intensity of the
light depends on its size.
Sampling
Falloff Type: Determines how the light will transition from full strength
to no lighting inside the light cone.
Photon Subdivs: This value is used by V-Ray when calculating the Global
Photon Map. Lower values mean more noisy results, but will render faster. Higher
values produce smoother results but take more time.
Caustic Subdivs: This option controls the amount of photons that V-Ray
will trace to estimate caustics (quality of the caustics). Large numbers slow
down the calculation of the caustics photon map and may use more memory.
Cutoff Threshold: This parameter specifies a threshold for the light
intensity, below which the light will not be computed. Larger values cut away
more from the light; lower values make the light range larger. If you specify
0.0, the light will be calculated for all surfaces.
Cone Angle: Allows you to adjust the angle of a light cone. Please see
the example below.
Cone Angle 0.2 |
Cone Angle 1.0 (Default) |
Cone Angle 2.0 |
Penumbra Angle: This is the angle from the edge of the spotlight’s
beam over which the intensity of the spotlight falls off to zero. Please see the
examples below.
Penumbra Angle 0.0 (Default) |
Penumbra Angle 0.2 |
Penumbra Angle 1.0 |
Penumbra Angle 0.0 (Default) |
Penumbra Angle 0.2 |
Penumbra Angle 1.0 |
Bumped Below Surface: This is used for cases where the light shines on
surfaces with extreme bump mapping. For such surfaces, it is possible that the
bump map will turn the surface normal towards the light, even though the light
shines on the back of the surface. The light option defines whether such
portions of the material will be lit or not.
Shadows
Shadow Color: Determines the color of the shadows.
Shadow Bias: Bias moves the shadow toward or away from the shadow-casting
object (or objects). If the Bias value is too low, shadows can "leak" through
places they shouldn’t, produce more patterns or make out-of-place dark areas on
meshes. If Bias is too high, shadows can "detach" from an object. If the Bias
value is too extreme in either direction, shadows might not be rendered at all.
Radius: This is the radius of the light source. If you increase this
value you can create softer shadows.
Shadow Subdivs: This value controls the number of samples V-Ray takes to
compute lighting (the quality of the shadows).
Decay: Normally, the light intensity is inversely proportional to the
square of the distance from the light (surfaces that are farther from the light
are darker than surfaces that are closer to the light). The possible types are:
- Linear: No Decay at all, and light remains at the same intensity.
The intensity will not decay with distance.
- Inverse Decay: An inverse relationship between the intensity of
the light and the distance it travels.
- Inverse Square Decay: Still an inverse relationship, but
intensity decreases much more rapidly. This is the physically correct
decay mode.
Barn Door On: This option enables or disables the barn door effect.
Barn doors restrict the light cone on the four sides of the light to produce a
rectangular light shape (in the real world, they are four planes attached in a
square around the light).
Barn Door Left: Allows you to control the left shutter value.
Barn Door Right: Allows you to control the right shutter value.
Barn Door Top: Allows you to control the top shutter value.
Barn Door Bottom: Allows you to control the bottom shutter value.
This is the kind of light that the barn door effect tries to mimic.
How to use Spotlights:
1. Click on the
icon to add a V-Ray Spotlight into your scene.
2. Click on the scene to select the location of the light.
3. Right click on the Spotlight, select V-Ray for SketchUp and then "Edit Light"
to enter the light options.
4. At this point you can adjust the setting of the Spotlight to get the
desired effect. If you are using the Physical Camera you might have to increase
the power to make the light visible.
5. Render your scene.
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