Blender for XNA Levi D. March 2013

Professional Use Can Blender be used for professional quality graphics? Elephants Dream (2006) Big Buck Bunny (2008) – Sintel (2010) – Tears of Steel (2012)

Views Selecting the view – Numpad 7: Top View – Numpad 1: Front View – Numpad 3: Right Side View – Numpad 5: Orthographic (see gridlines) – Ctrl + Numpad: Other side (bottom, back, left side) Note: All commands are for Blender 2.6

Cameras Numpad 0: Camera view Helpful for positioning view Ctrl + 0 select camera when using multiple cameras Right click on line between panes to split screen – Multiple concurrent views of scene F12 renders the current scene F3 saves image

Modes Change modes with Tab Object mode – Lock location and size for XNA – Location: (0, 0, 0) Size: (1, 1, 1) – Vertex coordinates in XNA are relative to orange anchor dot Edit mode – Select vertices, edges, faces – Move (translate), rotate, scale

Creating an Object A – Select All / Select None B – Box select E – Extrude X – Delete These can be applied to vertices, edges, and faces Ctrl + Mouse button – free select Z – fill object; select only one side

Modifying the Object G – Translate (move) R – Rotate S – Scale Follow operator by X, Y, or Z to lock movement to that axis Follow operator by number to translate, rotate, or scale by that value

Armature Add a bone to your object Select point on bone in edit mode and extrude to add new bones Make sure your bones are aligned with your object In object mode, select armature and object Ctrl + P, with automatic weights to assign armature to object

Weight Paint Select mesh in object mode, then select Weight Paint mode Used for finer control of assigning vertices to bones Change selected bone in object browser

Posing Pose mode to move armature – Must have armature selected to enter Pose mode Record button - automatic keyframing – Not recommended Dope sheet / action editor I, LockRotScale – insert keyframe – Must be in Pose mode! – Make sure all bones are selected (A) Can duplicate keyframe using select then Shift + D

Animation Walk cycle Ctrl + F12 to render images Images stored in Output folder (default C:\tmp) Select RGBA to keep transparency

Render a Face Start with default Cube Subsurf modifier – High value for CG image, low value for objects to be rendered in real time (games) Ctrl + R – Loop cut Mirror modifier – Delete half of the object Proportional Editing Tool – O Key

Render a Body Set background images as a guide Export FBX for XNA – Blender Z Up coordinate system – XNA Y Up coordinate system – Rotate 90 degrees on import – Both use Right Hand Rule – Select XNA Strict Options Skinned Model Processor Many models will cause slowdown – Hardware Instancing to draw multiple models efficiently

Other Useful Options F – Make face from selected vertices 3 or 4 selected vertices only Remove doubles (button) Change merge threshold if no vertices are removed Vertices to be merged must be selected Shift + D – duplicate object (or vertices/faces) Ctrl + J – join two objects Alt + F – fill (generate triangle faces for selected vertices) Ctrl + T – generate triangles faces from quad faces

Texture Mapping Split View Change new pane to UV/Image Editor UV Pane: Image > Open Image > Select your texture View Pane: Face Select Mode, then select faces View Pane: Mesh > UV Unwrap > Select unwrap method UV Pane: Scale and position vertices on texture Select Texture tab Set Type to Image or Movie

Texture Mapping continued Texture Tab: Under Image, select open and select the texture used Texture Tab: Under Mapping, select UV for coordinates Texture Tab: Under Mapping, select UVMap for map Press F12 to render the scene and the image should be correctly mapped onto the model Select specific faces in the View pane to see the corresponding points in the UV Pane

Importing into XNA Default Model object will handle non-moving models Texture must be imported separately SkinnedModelProcessor must be created to import animation data XNA will only use first animation defined in an FBX model

DepthStencilState Be sure to set to default when displaying models after displaying sprites

Special Techniques Billboarding Keeps flat objects facing towards the camera Trees in a racing game Text in a 3D world Atlas Mapping Render many similar objects at once Allows object texture changing without sacrificing processing time

What Else Can Blender Do Particle Systems Fluid Simulation

Sites to Check Out Blender 3D: Noob to Pro – Free online wiki book – Diabolical The Shooter – John C Brown Game developed using Blender models, with guides and tutorials Blasting Bits My game using Blender models, with development process documented

Books Foundation Blender Compositing Author: Roger Wickes Compositing-Roger-Wickes/dp/ Covers Blender 2.4, before user interface changes