ddg.blender.props module

ddg.blender.props.hide_previous(func: Callable[[P], Union[bpy.types.Collection, bpy.types.Object]], /) → Callable[[P], None][source]

Show and hide collections which depend on parameters.

Parameters:

funcCallable: A function that returns either a Blender object or collection. Every Blender object and collection returned by func must be created within func. Every parameter must be hashable.

Returns:

Callable: This function has the same signature as func. It caches the output and selectively hides Blender objects and collections returned by func such that only the last call is visible.

Examples

>>> import bpy
>>> import ddg
>>>
>>> @ddg.blender.props.hide_previous
... def f(x):
...     # The collection is created within f and cannot be factored out.
...     collection = ddg.blender.collection.collection("Collection")
...     p = ddg.arrays.Points((x, 0, 0))
...     # The object is created within f and cannot be factored out.
...     ddg.blender.convert(p, "Point", collection=collection)
...     return collection
...
>>> set(bpy.data.collections)
set()
>>> set(bpy.data.objects)
set()

Calling f creates a new collection.

>>> collection_0 = f(-5.3)

Note that the name of the collection and the Blender object it contains enumerate the number of calls to f.

>>> collection_0
bpy.data.collections['Collection 0']
>>> set(bpy.data.collections)
{bpy.data.collections['Collection 0']}
>>> set(collection_0.objects)
{bpy.data.objects['Point 0']}

The results of the last (in this case also the first) call to f are both visible.

>>> collection_0.hide_render
False
>>> collection_0.hide_viewport
False

Calling f again creates another collection.

>>> collection_1 = f(2.7)
>>> collection_1
bpy.data.collections['Collection 1']
>>> set(bpy.data.collections)
{bpy.data.collections['Collection 0'], bpy.data.collections['Collection 1']}
>>> set(collection_1.objects)
{bpy.data.objects['Point 1']}

The results of the previous calls to f are now hidden. In this example, only one collection, namely collection_0, is hidden. The results of the last call to f are visible.

>>> collection_0.hide_render
True
>>> collection_0.hide_viewport
True
>>> collection_1.hide_render
False
>>> collection_1.hide_viewport
False

If we pass -5.3 to f a second time, we will get the cached result.

>>> collection_0_again = f(-5.3)
>>> collection_0 == collection_0_again
True
>>> collection_0.hide_render
False
>>> collection_0.hide_viewport
False
>>> collection_1.hide_render
True
>>> collection_1.hide_viewport
True

ddg.blender.props.add_props_with_callback_from_constructors(callback: Callable[[...], Any], positional_labels_constructors: dict[str, Callable[..., Any]], keyword_labels_constructors: dict[str, Callable[..., Any]]) → None[source]

A more advanced version of add_props_with_callback().

Unlike add_props_with_callback(), this function doesn’t infer what kind of Blender property to add. Instead, property constructors must be explicitly specified, which allows for control over the minimum and maximum value, step sizes and other property types.

Parameters:

callbackCallable: This function is called whenever the properties’ value change.
positional_labels_constructorsdict[str, Callable[…, Any]]: The keys are the labels of the properties. The values are Blender property constructors whose values will be passed to callback as positional arguments.
keyword_labels_constructorsdict[str, Callable[…, Any]]: The keys are the labels of the properties. The values are Blender property constructors whose values will be passed to callback as keyword arguments.

Raises:

ValueError: If the labels aren’t unique.