Working with mesh geometry, it may be necessary to assign each vertex some custom properties or data that must be written to the blend-file when saved, and which must be accessed later.
However, an attempt to assign the necessary data to the vertexes through the creation of custom properties fails. Instead of the custom vertex property, only a tuple with reference to the type of the property is created.
A set of operators is provided in Blender for manipulating with the location of its interface windows.
To split the current window (using the current context) into two in a specified ratio, we need to execute the following operator:
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bpy.ops.screen.area_split(direction='VERTICAL', factor=0.5) |
With:
How to split and join Blender interface windows thruough the python APIRead More »
The Blender API provides a set of simple property types described in bpy.props (IntProperty, BoolProperty, etc.). But the basic types are not always enough, sometimes we need more complex ones. The Blender API allows to group simple properties to make complex properties.
Let’s consider such complex property creation and make the 3×3 matrix property as an example.
To get current Blender version number through the Python API we need to execute the following command:
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bpy.app.version # (2, 81, 16) |
or
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bpy.app.version_string # '2.81 (sub 16)' |
How to get current Blender version number through the Python APIRead More »
The Blender 2.80 API provides the ability to draw in a viewport (3D Viewport) using the “gpu” module.
As an example let’s draw a simple coordinate system widget in the center of the scene, consisting of three lines with different colors.
The button click is basically connected with the operator calling in the Blender user interface. However, some times actions, that need to be performed when a button is pressed, are quite simple and do not require a separate operator for them. And it makes no sense to fill a registered operators stack with a multitude of specific operators designed to perform one highly specialized function. It would be much more convenient to associate a button press with a separate function call but the Blender API allows to associate buttons only with an operator call.
To solve the problem of creating a separate operator for each button we can use the fact that the operator can be called with the input parameters.
Calling functions by pressing buttons in Blender custom UIRead More »
To correctly set values to an EnumProperty type we need to know all its possible entries.
If we try to set a value to an EnumProperty that is out of its available variants, Blender will throw an error:
TypeError: bpy_struct: item.attr = val: enum “xxx” not found in (‘value_001′, value_002’, …)
where:
xxx – the value we tried to set to an EnumProperty
value_001, value_002, … – possible EnumProperty values
How to get a list with all possible values of an EnumPropertyRead More »
To translate cursor to the desired mesh vertex execute the following code:
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bpy.context.scene.cursor.location = bpy.context.object.matrix_world @ bpy.context.object.data.vertices[_VERTEX_NUMBER_].co |
Attention to the multiplication order – world matrix should be left.
In Blender 2.79 Python API we can add a new object to a scene with:
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bpy.context.scene.objects.link(new_object) |
If we try to do this in Blender 2.80, it throws an error:
‘bpy_prop_collection’ object has no attribute ‘link’
In Blender 2.80 API new objects mast be linked not to the scene, but to the scene collections:
To link a new object to the active scene collection:
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bpy.context.scene.collection.objects.link(new_object) |
To link a new object to the collection by its name:
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bpy.data.collections['collection_name'].objects.link(new_object) |
To move the cursor to the start position of the active strip in Blender VSE:
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bpy.context.scene.frame_current = bpy.context.scene.sequence_editor.active_strip.frame_start |
To move the cursor to the end position of the active strip:
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bpy.context.scene.frame_current = bpy.context.scene.sequence_editor.active_strip.frame_final_end |