VRay for SketchUp New Features Guide
Lights: IES Lights
V-Ray for SketchUp new light type can be used to load and render real-world
light distribution profile files
(IES files - Illuminating Engineering Society). The icon is located in the V-Ray
Enabled: Turns on or off the IES lights.
Shadows: Turns on or off the IES shadows.
Soft Shadow: This causes the light to take into account the information
about the light shape in the IES file (if there is any shape defined) so that it
produces proper soft 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 render at all.
Shadow Subdivs: This value controls the number of samples V-Ray takes
to compute lighting (the quality of the shadows). Lower values mean more noisy
results, but will render faster. Higher values produce smoother results but take
more time. Note that the actual number of samples also depends on the DMC
File (picker): Allows you to load the IES file that defines the light
Filter Color: This parameter determines the color of the light.
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.
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 Speculars: When this option is Off, the particular light will be
rendered as a point light in the specular reflections.
Power: Determines the intensity of the light in lumens. A typical 100W
electric bulb emits about 1500 lumens of light.
Cutoff Threshold: This parameter specifies a threshold for the light
intensity, below which the light will not be computed. This can be useful in
scenes with many lights, where you want to limit the effect of the lights to
some distance around them. 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.
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 take more memory.
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.
How to use IES Lights:
1. Click on the IES light
icon to add a
V-Ray IES light to your scene.
2. Click on the scene to select the location of the IES light.
3. Right click on the IES light, select V-Ray for SketchUp and then "Edit
4. Click on "File" to load an IES file from your hard drive.
5. At this point you can adjust the setting of the IES light to get your desired
effect. For example, if you are using the Physical Camera you might have to
increase the power to make the light visible. Also you can change the "Filter
Color" to control the color of the light.
6. Render your scene.
The unit for the V-Ray IES light is in lumens and a typical 100W
electric bulb emits about 1500 lumens of light. For this reason when
you are using the physical camera you might use a very high value.
The physical camera will control the exposure of the sun and also
reduce the brightness of every other type of light.
Once you created an IES light you have to scale the icon to your
desired position. Remember the lower part of the cone is the light
emitter. Do not close that part inside of the other surface because
you can hide the IES light.