Turtle attributes on shape nodes

To view the following attributes in the Attribute Editor, select an object and expand the Turtle section in its shape node.

Subdivision Settings

Select TURTLE > Add Subdivision Attributes, to add the following attributes to the Attribute Editor window.

Render as Subdivision Surface

When enabled, Turtle uses subdivision. Turtle supports polygons with a maximum of 5 edges.

Subdivision Depth

Controls the amount of subdivision that occurs. A higher value produces more polygons and a better result, but also uses more memory and increases render times.

Sharp Corners

When enabled, the corners of a open mesh remain sharp. A sphere is a closed mesh, a plane is an open mesh.

Smooth UV
When enabled (default), applies the same smoothing operation to the UVs as to the vertices. Smooth UVs is on by default, providing better results for UVs.

Render Stats

Select TURTLE > Add Render Stats Attributes to add the following attributes to the Attribute Editor window. This section sets general parameters for how objects interact with light.

Smooth Normals

The normals of a mesh can be smoothed at render time. The normals are then calculated as the average of all vertex normals at the same vertex. A threshold can be used to only include normals which have a similar direction. The threshold is given as the maximum angle in degrees, between two normals, under which they will be averaged.

For example, when using pre-tessellated displacement you often need a very high tessellation setting to get a smooth looking surface. By smoothing the normals on faces that don't have too sharp edges, you can get a smooth looking surface with much lower tessellation settings, saving both memory and render time.

When calculating surface transfer from a mesh with face normals you will not get a continuous sampling since the sampling is performed along the normals of the mesh. Enabling Smooth Normals produces a continuous sampling without having to alter the actual normals on the model.

Note: When tessellating NURBS surfaces, Turtle tries to match Maya LT’s render tessellation. In some cases the normals can differ over a surface seam, resulting in shading artifacts. If this happens, enable Smooth Normals on the object.
Normal Threshold
Visible in Final Gather

Lets the object affect final gather calculations.

Static Final Gather

When enabled, the object keeps its final gather samples in RAM-memory between successive frames in an animation.

Smooth Final Gather

When enabled, the final gather solution is smoothed for the object. When disabled, the final gather smoothing is disabled, which might save render time in some situations.

Cast Global Illumination
When enabled, the object reflects indirect light.
Receive Global Illumination
When enabled, the object receives indirect light.
Cast Occlusion

If disabled, the object will be invisible for occlusion rays. Therefore, it will not cast any occlusion on other objects when the ilrOccSampler is used.

Receive Occlusion

If disabled, the object will not receive any occlusion from other objects when the ilrOccSampler is used.

Self Occlusion
Bias Shadow Rays

Enable Bias Shadow Rays to reduce shadow line artifacts on low-resolution geometry.

Global Illumination Settings

Final Gather Override

Final Gather Override
Lets you override the settings of the final gather attributes. For a full description of these attributes see Global Illumination Tab.

Path Tracer Override

Path Tracer Override
Lets you override the settings of the path tracer attributes. For a full description of these attributes, see Path Tracer.
Filter Type

Selects the filter to use when querying the cache during rendering. None returns the closest cache point (unfiltered).

Filter Size
Sets the size of the filter as a multiplier of the Cache Point Space value. For example, a value of 3.0 uses a filter that is three times larger than the cache point spacing. If this value is below 1.0, there is no guarantee that any cache point is found. If no cache point is found, the Default Color is returned for that query.

Monte Carlo Override

Monte Carlo Override

Lets you override the settings of the monte carlo attributes. For a full description of these attributes, see Global Illumination Tab.

Rays

Global Photon Map Override

Global Photon Map Override

Lets you override the settings of the global photon map attributes. For a full description of these attributes, see Global Illumination Tab.

Accuracy

Sets the number of photons to use when calculating global illumination effects. A higher number gives higher quality but takes a longer time to calculate.

Radius

Sets the maximum search radius to use when searching for photons during lighting calculations for global illumination effects. If the Photon Radius is set to r, photons within a sphere of radius r around the sample point will be used to calculate the light. If the Photon Radius is set to 0.0 a value will be calculated automatically based on the size of the scene. The automatic value will be printed out during rendering, which is a good starting value if the point spacing needs to be adjusted.

Caustics Override

Caustics Override

Lets you override the settings of the caustics attributes. For a full description of these attributes, see Global Illumination Map.

Accuracy

Influences the number of photons to use when calculating caustics effects, a higher number take more photons into account. Default value is 1.0.

Radius

Sets the maximum search radius to use when searching for photons during lighting calculations for caustics effects. If the Photon Radius is set to r, photons within a sphere of radius r around the sample point will be used to calculate the light. The radius is given in Maya units.

Bake Resolution Override

Select TURTLE > Add Bake Attributes to add the following attributes to the Attribute Editor window.

Bake Resolution Override

When enabled, lets you to override the settings of the texture baking attributes Bake Res X, Bake Res Y, and Bake Set Scale for a particular object. For a complete explanation of these attributes see