Starbase Graphics Performance
Optimized vs. Normal 3D Performance
Performance Optimized For: | Factors Affecting Performance: | |
Rendering | Conditions | |
• Best: up to 8 directional light sources, plus | • | A total of more than 8 directional and |
ambient |
| positional light sources cause a noticeable |
• Good: a mixture of up to 8 directional and | • | performance degradation |
positional light sources, plus ambient | Picking | |
• Directional eyepoint set with view_point | • | Any of the following ways of heavily |
• Back face culling off, or back face culling |
| interleaving changes: |
on with supplied geometric normals |
| o Frequent attribute changes (e.g., |
• View clipping on |
| frequent changes of line color) |
• Isotropic modeling matrix (angle- |
| relative to the number of primitives |
preserving) |
| being drawn |
• shade_mode set to CMAP_FULL |
| o Frequent changes of the type of |
|
| primitive (e.g., switching between |
|
| polygons with polylines at a high |
|
| frequency) |
|
| o Frequent changes of vertex format |
|
| (i.e., the data being supplied with |
|
| each vertex) |
|
| o Frequent changes of modal state, |
|
| such as: |
|
| |
|
| |
|
| Shade mode |
|
| Light sources enabled |
|
| Depth cueing state |
|
| Texture mapping state |
|
| o Frequent switching between two or |
|
| more file descriptors |
|
| o Frequent mixing of Xlib and |
|
| Starbase calls |
| • Redundant or unnecessary setup (e.g. | |
|
| setting attributes that are not relevant to the |
| • | primitives being drawn) |
| Deformation on | |
| • | Model clipping on |
| • HLHSR in software via PowerShade (on | |
|
| unaccelerated graphics devices) |
Page 112 | Graphics Administration Guide for |