Graphics, Modeling, and Textures

Computer Game Design and Development

Graphics Considerations

• Frame and back buffers– Avoid artifacts (jitter and visible drawing)– Swap or copy?

• Depth and stencil buffer• Triangles– Easily interpolate– Planarity

• Vertices & coordinate space

Depth Bits

From http://www.agidev.com/articles/a.php?id=6&page=4

Limiting What we Render

• View frustrum– Near and far planes

• Clipping • Cull when possible– Render Volume Partitioning

Backface Culling

Quadtree partitioning

• Collision detection• Outdoor visibility checking

• Algorithm (2D):– X/Y : consider bits– Left shift at each level in tree– When at leaf, stop

Quadtree Visualized

Graphic Primitives

Mesh as Triangle Strip

Indexed Strips

Applying Textures

Lightinghttp://machinesdontcare.wordpress.com/2008/06/

http://www.directxtutorial.com/Tutorial9/B-Direct3DBasics/dx9B3.aspx

Modeling

Modeling (cont)

Using Normal Maps and Textures

Normal Maps and LOD

http://www.inition.co.uk/inition/product.php?SubCatID_=38&URL_=product_ffhaptic_sensable_claytools

http://upload.wikimedia.org/wikipedia/commons/3/36/Normal_map_example.png

Level of Detail

• Hardware limits number of polys rendered• Use high-level models when possible• Drop to low poly models (LOD) when needed

Level Editing

• Target fixed poly count (thought allow for flexibility and customization)

Low-Poly Count Modeling

Final thoughts

• Major difference in modeling and using models

• Art & programming & level/character design

• Take graphics in summer!