To view the following attributes in the Attribute Editor, select a light and expand the Turtle section in its shape node.
Select TURTLE > Add Intensity Attributes to add the following attributes to the Attribute Editor window. This section contains settings for emitting photons.
Scales the light intensity for primary rays. Can be used to adjust or turn on/off the amount of light this light source emits on surfaces visible from the camera.
Scales the light intensity for reflection rays. Can be used to adjust or turn on/off the amount of light this light source emits on surfaces visible in reflection.
Scales the light intensity for refraction rays. Can be used to adjust or turn on/off the amount of light this light source emits on surfaces visible in refractions.
Scales the light intensity for final gather rays. Can be used to adjust or turn on/off the amount of indirect light this light source emits.
Any light source can now be turned into an indirect light. Behaves like a normal light, but instead of the standard light shader it uses the indirect (GI) solution as light shader. This way you can light link the GI, saturate the GI color, shape the GI in form of a spotlight. Basically all controls you have on the direct light sources can be used to control the GI solution.
Select TURTLE > Add Decay Attributes to add the following attributes to the Attribute Editor window. This section contains settings for emitting photons.
Sets a radius of influence for this light source. Inside the sphere spanned by the radius light is emitted as usual, but outside the sphere no light is emitted. This will also optimize shadow calculations since no shadow rays will be cast from surfaces outside the sphere.
Enable this if you want a light decay that is a function of the radius of influence. The following formula will then be used to calculate the illumination: illumination = color * intensity * [1.0 - (distance/radius)d]f.
Controls the d exponent in the formula above. Can be used to adjust the shape of the light attenuation.
Controls the f exponent in the decay formula above. Can be used to adjust the shape of the light attenuation.
Select TURTLE > Add Shadow Attributes to add the following attributes to the Attribute Editor window. This section contains settings for emitting photons.
Sets the minimum number of shadow rays used to determine the influence of this light source a any point. Use this setting to ensure that you get enough quality in the soft shadows for this light source at the price of render times. If this is set to zero, Turtle determines a good value for this setting, otherwise the number specified is used. Regardless of the value specified, there will never be more rays sent than specified in the Shadow Rays setting for 45 the light source or more than the Max Shadow Rays setting specified in the Overrides section of the Render Settings for Turtle.
Enables Turtles Depth Map Shadows. When this checkbox is enabled, Turtle will use the settings below for shadow calculation. If this checkbox is disabled and Maya’s Depth Map Shadows are enabled, Turtle will calculate shadows based on Maya’s Depth Map Shadows settings.
Sets the resolution of the depth map used for calculating shadows. A higher resolution will give less aliasing but consume more memory. If a very soft shadow is desired, set a low resolution and use a large filter size.
The size of the blur filter kernel. A larger value will give a softer shadow. If a low resolution is set, a larger filter size is needed to reduce aliasing.
Sets the number of samples to use then applying the filter to get soft shadows. A higher value will give less noise but longer rendering time.
The bias used to reduce self-shadowing artifacts. If Mid Distance is used, this value can often be ignored.
This is used to reduce self-shadowing artifacts. When this is enabled the average distance between the first and the second intersection will be stored in the depth map.
Controls the usage of depth map files. By saving the depth map to a file it can be reused in successive renderings. Note that if the light or shadow casting objects are moved recalculation is necessary. The file is written to the folder turtlendepthMaps in the current project directory.
Creates a new depth map file, overwriting any existing file. Reuse loads the depth map from a previously created file.
Loads the depth map from a file, but also writes back new depth map tiles generated during rendering.
Sets the file name for the depth map file.
Select TURTLE > Add Light GI Attributes to add the following attributes to the Attribute Editor window. This section contains settings for emitting photons.
Select TURTLE > Add IES Attributes to add the following attributes to the Attribute Editor window.
Turtle has support for light profiles on point lights. With light profiles, you can easily add real-life lights to your scene for greater realism. A light profile is a light intensity distribution specified by a texture map.
The file name of the IES Light profile to use. Turtle can read so called IES-files. Many manufacturers of lighting fixtures record photometric light intensity measurements of their products in IES-files and provide these for visualization purposes online.