Optimized vs. Normal 3D Performance
Performance Optimized For: | Factors Affecting Performance: | |
| Rendering | Conditions |
• Light Sources: | • A total of more than 8 directional and | |
o Best: up to 8 directional light | positional light sources cause a noticeable | |
| sources, plus ambient | performance degradation |
o Good: a mixture of up to 8 | • Picking (including direct pick and logical | |
| directional and positional light | device picking) |
| sources, plus ambient | • Any of the following ways of heavily |
• Directional eyepoint, set via: | interleaving changes: | |
o | pescape_u230/pgse_u3 (C), | o Frequent attribute changes (e.g., |
| pue230/pus003 (FORTRAN) | frequent changes of line colour) |
• Back face culling off, or back face culling | relative to the number of primitives | |
on with supplied geometric normals | being drawn | |
• View clipping on, set via: | o Frequent changes of the type of | |
o | pset_view_rep (C), psvwr | primitive (e.g., switching between |
| (FORTRAN) | Fill Areas and Polylines at a high |
• True colour mapping in a direct colour | frequency) | |
environment | o Frequent changes of vertex format | |
• Isotropic modeling matrix (angle- | (i.e., the data being supplied with | |
preserving) | each vertex) | |
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| o Frequent changes of modal state, |
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| such as: |
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| HLHSR mode or ID |
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| Colour mapping method |
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| Light sources enabled |
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| Depth cueing state |
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| o Frequent switching between two or |
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| more active workstations |
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| o Frequent mixing of Xlib and hp- |
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| PHIGS calls |
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| • Redundant or unnecessary setup (e.g. |
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| setting attributes that are not relevant to the |
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| primitives being drawn) |
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| • Model clipping on |
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| • HLHSR in software via PowerShade (on |
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| unaccelerated graphics devices) |
Page 109 | Graphics Administration Guide for |