Composite pieces

Objectives

In this station a figure for the halma game will be created. It is a composition from mesh objects (primitives).

Instructions

Tasks:

1. Create a composite pice as shown in this learning unit.
2. Move the new object with the mouse.
3. Join the parts and name the object »halma_figure«.
4. Move the new object again.
5. Duplicate the object and have a look at the counter in the header of the info window.

First version

#! bpy
"""
Name: 'halma_figure.py'
Blender: 269
Group: 'Example composit piece'
Tooltip: 'Crate and add a halma figure'
"""
import bpy


def halma_figure():
    '''Crate a halma figure from a ball and a cone'''

    # get the context
    scn = bpy.context.scene

    # names of the parts
    parts = ['head', 'body', 'halma_figure']

    # crate the head
    bpy.ops.mesh.primitive_uv_sphere_add(location=(2, 2, .9))
    obj = bpy.context.object
    obj.scale[0] = .6
    obj.scale[1] = .6
    obj.scale[2] = .6
    obj.name = parts[0]

    scn.objects.active = scn.objects[parts[0]]

    # create the body
    bpy.ops.mesh.primitive_cone_add(location=(2, 2, 0))
    obj = bpy.context.object
    obj.scale[0] = .8
    obj.scale[1] = .8
    obj.name = parts[1]
    scn.objects.active = scn.objects[parts[1]]

if __name__ == '__main__':
    bpy.ops.object.select_by_type(type='MESH')
    bpy.ops.object.delete()
    halma_figur()

Select the context

Selecting the context is the first step. Next step is creating and positioning objects. The context is assigned to a variable named scn.

    # get the context
    scn = bpy.context.scene

Name it

If you name the objects, later on it is easier to select one of them.

    # names of the parts
    parts = ['head', 'body', 'halma_figure']

First part of the composite pice

The sphere is the first part. We also scale the object afterwards and name it »head«.

    # crate the head
    bpy.ops.mesh.primitive_uv_sphere_add(location=(2, 2, .9))
    obj = bpy.context.object
    obj.scale[0] = .6
    obj.scale[1] = .6
    obj.scale[2] = .6
    obj.name = parts[0]

Second part of the composite pice

Same procedure as with the first part.

    # create the body
    bpy.ops.mesh.primitive_cone_add(location=(2, 2, 0))
    obj = bpy.context.object
    obj.scale[0] = .8
    obj.scale[1] = .8
    obj.name = parts[1]
    scn.objects.active = scn.objects[parts[1]]

Call the function

Let’s have a look to the final version. Are all pieces on the right place and have the right dimension? The old objects are deleted, so a frech and empty scene is used. You can check the info window. There are also statistics about the number of objects.

if __name__ == '__main__':
    bpy.ops.object.select_by_type(type='MESH')
    bpy.ops.object.delete()
    halma_figur()

How many objects are selected/available?

How to connect the parts to one?

Add the following lines of code to glue together the two pieces to a new one.

# connect parts to a new one
scn.objects[parts[0]].select = True
scn.objects[parts[1]].select = True
bpy.ops.object.join()
obj.name = parts[2]