Blender Scripting COSC450. Material for Assignment 1

Transcription

1 Blender Scripting COSC450 Material for Assignment 1

2 Blender Blender is a free 3D graphics package I 3D object modelling I Materials and lighting I Animation and simulation I Video editing and compositing I Integrated physics engine I Free download, installed in labs COSC450 Blender Scripting 2

3 Blender Scripting Blender can be scripted with Python Uses Python 3 Just about everything can be scripted Creating objects, lights, cameras Creating and applying materials Rendering and animation The Blender interface itself Huge changes from Blender 2.4 to 2.5 Three main components bpy.data contains objects, scenes, materials, etc. bpy.context information about current state - e.g.: selected objects bpy.ops operations on the scene such as adding an object, rotation, etc. COSC450 Blender Scripting 3

4 How do I Script X? If you know how to do something in the Blender UI Hovering over interface elements shows the equivalent Python function You can make an Info window which reports operations as they are applied You can always ask the internet Check for version 2.5 or later! COSC450 Blender Scripting 4

5 My Usual Scripting Setup COSC450 Blender Scripting 5

6 A Simple Blender Script import bpy for s in range (1,10) : # Set the cursor location to 2s units along y - axis bpy. context. scene. cursor_location = (0, 2* s, 0) # Create a sphere at the cursor sphere = bpy. ops. mesh. primitive_ico_sphere_add () # Select ( just ) the newly created sphere bpy. context. selected_objects. clear () bpy. context. selected_objects. append ( sphere ) # Squash the selected object bpy. ops. transform. resize ( value =(0.5, 1.0, 0.5) ) # Add a light bpy. ops. object. lamp_add ( type = POINT, location = (3, 2, 1)) COSC450 Blender Scripting 6

7 Scripting Materials First you need to define a material Diffuse component (basic colour) Specular component (shine) Transparency, mirror reflections etc. Then you can apply it to an object Can also make textures etc. Usually easiest to work in the UI first COSC450 Blender Scripting 7

8 A Simple Material Script # Make a new material mymaterial = bpy. data. materials. new (" materialname ") # Diffuse colour component mymaterial. diffuse_color = (1.0, 0.0, 0.0) mymaterial. diffuse_shader = LAMBERT mymaterial. diffuse_intensity = 1.0 # Specular colour component mymaterial. specular_color = (0.0, 1.0, 0.0) mymaterial. specular_shader = COOKTORR mymaterial. specular_intensity = 0.75 mymaterial. specular_hardness = 15 # Apply it to the active object bpy. context. object. data. materials. append ( mymaterial ) COSC450 Blender Scripting 8

9 Cameras and Rendering Cameras are just like any other object You can add them to the scene You can apply operations to them To render a scene Set an active camera Choose an image filename Set any other parameters Render a single frame COSC450 Blender Scripting 9

10 Rendering Script Example # Add a camera bpy. ops. object. camera_add ( location =(10, 10, 0), rotation =(1.5,0,2.5) ) # Give it a name for ease of reference bpy. data. cameras [0]. name = Camera # Activate this camera bpy. context. scene. camera = bpy. data. objects [ Camera ] # Choose an image filename # Note that // is the directory of the. blend file bpy. data. scenes [ Scene ]. render. filepath = // img. png # Render a single ( still ) image bpy. ops. render. render ( write_still = True ) COSC450 Blender Scripting 10

11 Python Issues in Blender Python script fail, look in console This is not Blender s python console It is the system console Launch Blender from the terminal Using multiple scripts Can make multiple files in the editor These create modules Modules don t automatically update import imp # or importlib import Module imp.reload(module) COSC450 Blender Scripting 11

12 Blender Resources Blender homepage: The sample script will be available on the website Also a more complex script that makes planetary systems The COSC342 pages may be useful: COSC450 Blender Scripting 12