Overriding Properties

Overrides are used to temporarily replace the current values of parameters. They are useful for controlling one or more specific parameters of a group, layer, or partition, without losing each object’s individual parameter values.

For example, suppose you have a group of polygon mesh objects, each of which has different subdivision levels applied in its Geometry Approximation property. Suppose you want to control all their OGL Level parameters together, but leave their individual Render Level parameters unchanged. If you apply a Geometry Approximation parameter to the group, it will affect all Geometry Approximation parameters through propagation. However, by using an override you can pick out just the parameter you want and modify it alone.

Overrides can be applied to individual objects, hierarchies (in branch mode), models, groups, and layers. However, they are especially useful for rendering passes because you can control specific properties (for example, transparency, shadow settings, or even the entire material) of all objects in a partition at once.

Overrides can contain individual parameters or entire property sets and materials.

Parameter overrides can be can be applied to objects, branches, groups, layers, and partitions, as well as with models.

Property set and material overrides can be applied to models — for example, you can transfer changes you made on one model to another version of the same model.

Property set and material overrides rely on object names within the model to determine which property on which object to override. For example, if you create an override for body.geomapprox on Model and transfer it to Model1, it will override the geometry approximation property of the object named body in Model1.

For information about using overrides on partitions in render passes, see Applying and Overriding Properties on Partitions [Rendering].

Overrides follow the same propagation rules as properties. For example, a local property on an object will take precedence over an override of a branch property. For more information about propagation, see How Properties Are Propagated.

 

Override nodes appear in the explorer as an O on a green background. The superimposed B indicates that the override was applied in branch.

 

In property editors, the animation icon of parameters that are controlled by overrides show a black triangle on a cyan background. Right-click the icon and choose Inspect Override to open the override’s property editor.

 

• You can still set the value of the object’s parameter but it has no effect as long as the parameter is overridden.

• Using overrides can bypass the maximum and minimum values allowed for parameters. Setting a value outside the allowable range can cause unpredictable results.

To create an override

1. Select the element on which you want to apply the override. You can select an object, branch, model, group, layer, partition, or even the scene root.

2. Choose Get > Property > Override from any toolbar.

An override is created, but has no parameters at this point. You need to add parameters or properties to the override to control them.

To add parameters or properties to an override

1. Open the override’s property editor.

2. Click Add Parameters. A pop-up explorer opens.

3. Do any of the following:

- Click to select a single parameter or property set and deselect any others.

- Shift+click to add a parameter or property set to your selection.

- Ctrl+click to toggle a parameter or property set.

- Ctrl+Shift+click to deselect a parameter or property set.

Selected parameters and property sets are highlighted in a light purplish blue.

4. When you have finished picking, click outside of the pop-up explorer. The selected parameters or property sets are added to the override.

- For parameters, you can use the sliders in the override property editor to control the values of the parameters in the scene.

- For property sets, you must open the property under the override in the explorer to control the values in the scene.

 

 

Property set overrides have an effect only when the override is applied on a model or the scene root. You can transfer the override by dragging and dropping in an explorer.

To remove parameters and property sets from an override

1. Open the override’s property editor.

2. Mark the parameter or property set to remove (click its name in the property editor). Shift+click to mark additional items.

3. Click Remove Marked Parameters.

To create an override for specific property sets

Certain property sets are commonly used in overrides, and there are special commands for creating overrides that contains exactly these properties.

1. Select or branch select a model.

2. Choose one of the following commands from the Get > Property > Store in Override submenu of any toolbar:

- Materials. Creates an override containing the model’s materials.

- Visibility. Creates an override containing the model’s Visibility property.

- Geometry Approximation. Creates an override containing the object’s Geometry Approximation property.

To create an override for selected property sets

1. Create an override on a model.

2. Multi-select the override and the property sets you want to add.

3. Choose Get > Property > Store in Override > Selected Properties from any toolbar.

To delete an override

• Select the override property and press Delete.

To delete all overrides on an element

• Select the element and choose Get > Property > Delete Override from any toolbar.

If you select a child node, this will also remove any overrides applied in branch mode on its parents. Similarly, if you select a member of a group, layer, or partition, this will remove any overrides on all groups, layers, and partitions to which the object belongs.

 

 



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