3D Models, Textures and Bone Animations for Games.

Overview: Tools – Advantages & Disadvantages Tools – Advantages & Disadvantages Low-poly models – from scratch Low-poly models – from scratch Texturing – UV maps and skins Texturing – UV maps and skins Bone Animation – setting up skeleton, inverse & forward Kinematics Bone Animation – setting up skeleton, inverse & forward Kinematics

The Tools Blender Blender Maya * Maya * 3DS 3DS Wings 3D Wings 3D Ultimate Unwrap * Ultimate Unwrap * Caligari Truespace * Caligari Truespace * Photoshop * Photoshop *

Blender –Pros: Free, Relatively Powerful. Free, Relatively Powerful. Can do skeletal animations. Can do skeletal animations. Easy to import/export. Easy to import/export. –Cons: Learning Curve; Learning Curve; counter-intuitive, “clunky” interface. counter-intuitive, “clunky” interface.

Maya Pros: Pros: –Extremely powerful. –Well documented. –Elegant, fast interface. –Becoming industry standard. Cons: Cons: –~$2,000. –Very good, but not excellent UV mapping

3DS Pros: Pros: – Very powerful. –Similar to Maya Cons: Cons: –Expensive.

Wings 3D Fast. Fast. –Easy to use. –Can make excellent Low-Poly models Cons: Cons: –No animation / UV mapping. – Hard to make complicated / High-poly models

Ultimate Unwrap Pros: Pros: –Best UV mapping tool on the market (in my opinion) –Very fast, simple interface. View texture on model in 3D environment. View texture on model in 3D environment. Automatically updates texture when saved Automatically updates texture when saved All the functionality of more expensive tools All the functionality of more expensive tools –Cheap (~$70) Cons: Cons: –Only good for UV mapping –Not directly compatible with Maya Need to “juggle” model formats *.obj -> *.mb Need to “juggle” model formats *.obj -> *.mb

Caligari Truespace Pros: Pros: –Relatively powerful Decent skeletal animations Decent skeletal animations UV mapping UV mapping –Cheap (couple hundred $ for latest version) Cons: Cons: – Extraordinarily awkward interface – Somewhat slow

Photoshop A necessity A necessity Uses Layers Uses Layers Highly Versatile tool set Highly Versatile tool set Great for creating skins to texture models Great for creating skins to texture models

3D Modeling Technique Art through extrusion Art through extrusion Minimize Polygons Minimize Polygons

Art through Extrusion Start with basic shape (cube) Start with basic shape (cube) –Extrude a Face –Adjust size of face –Collapse vertices / edges to make angles –Repeat above Use Symmetry Use Symmetry

Minimize Them Polies! Use triangular points (when possible) Use triangular points (when possible) Focus attention on salient areas Focus attention on salient areas Rely on texturing for detail – keep it simple Rely on texturing for detail – keep it simple Orient human models in standard position (shown) Orient human models in standard position (shown)

Some Buildings… Both < 20 polies Both < 20 polies

Some Space Ships… Both <80 polies

UV / Texture Mapping Different Types Different Types Methods Methods Minimize Size of Images Minimize Size of Images

There’s more than one way to Skin a Cowboy… Face Painting Face Painting –Paint a fixed texture to individual faces Pros: easy, fast Pros: easy, fast Cons: looks atrocious up close Cons: looks atrocious up close Materials Materials –Apply a “material” or surface texture to a face Phong, Metallic, etc. Phong, Metallic, etc. Diffuse, Ambient, Emissive, Specular, lightings Diffuse, Ambient, Emissive, Specular, lightings Pros: Looks really good. Pros: Looks really good. Cons: Requires in-game light source. Expensive. Cons: Requires in-game light source. Expensive. UV Mapping * UV Mapping * –“Unwrap” polygon model to flat surface –“Paint a picture” over unwrapped polies Pros: Can make low-poly models look good! Pros: Can make low-poly models look good! Cons: Difficult to learn / do well. Cons: Difficult to learn / do well.

UV Mapping Import Model Import Model Unwrap as desired Unwrap as desired Create Texture Create Texture

Import Model Disorganized UV map Disorganized UV map

Unwrap Model as Desired Many Different Types Many Different Types –Box, cylindrical, plane, etc. Make it “easy to paint” Make it “easy to paint” Conserve space Conserve space Devote more space to salient parts Devote more space to salient parts

Paint Texture Onto Model Use many layers (Photoshop / PSP) Use many layers (Photoshop / PSP) Low opacity Air Brush for shading Low opacity Air Brush for shading Darken Edges & Brighten centers of polygons Darken Edges & Brighten centers of polygons –Gives a more “rounded” appearance Keep textures small! Keep textures small!

Skeletal Animations (Maya) Set up Skeleton Set up Skeleton Organize bones into Hierarchy Organize bones into Hierarchy Inverse / Forward Kinematics Inverse / Forward Kinematics Skinning Your Character Skinning Your Character Get the MOST from your model Get the MOST from your model

Set up Skeleton Maya: Skeleton -> Joint Tool Maya: Skeleton -> Joint Tool Be anatomically accurate Be anatomically accurate Start from pivot; work outward Start from pivot; work outward Use at least 2 perspectives Use at least 2 perspectives

Use Mirror Joint Orient Model to the Origin!!! Orient Model to the Origin!!! Only way to ensure symmetry Only way to ensure symmetry Much easier Much easier Mirror Joint Mirror Joint –Select highest-order bone: hip –Maya: skeleton -> mirror joint

Use Hypergraph Label bones Label bones Organize into hierarchy Organize into hierarchy –Click / drag

Bind to Skin Attaches skeleton to model Attaches skeleton to model Maya: skin -> bind skin -> smooth bind+ Maya: skin -> bind skin -> smooth bind+ –Set max influence = 1 –Too many slows down in-game animation

Time to Animate Set a “neutral pose” Set a “neutral pose” –Select All –Key Everything at time = -10

Inverse Kinematics Use IK Handles Use IK Handles –Maya: Skeleton -> IK Handle Tool Allows fast and positioning Allows fast and positioning

OH NO! Sometimes difficult to get specific pose… Sometimes difficult to get specific pose… Then use Forward Kinematics Then use Forward Kinematics

Have animation reference Easy to google Easy to google Search for image displaying desired animation keyframes Search for image displaying desired animation keyframes

Loop Animations Save Effort – Copy / Paste Keyframes Save Effort – Copy / Paste Keyframes –Click on keyframed object / IK handle –Right click on Maya Timeline -> copy –Move timeline -> paste

Create more animations Skip a few frames Skip a few frames Select all Select all Key all Key all –So animations don’t interpolate between each other Skip a few more frames Skip a few more frames Have at it! Have at it!

Export your Animation Can download exporter from Ogre3d site Can download exporter from Ogre3d site