Sample demonstrating Anti-aliasing options that can be configured within Graphic3d_RenderingParams structure returned by V3d_View::ChangeRenderingParams().
Anti-aliasing algorithms are intended to solve the problem of jagged and pixelated edges. Interactive options:
Graphic3d_RenderingParams::NbMsaaSamples allows enabling multi-sampling anti-aliasing (MSAA) with specified number of samples within graphics hardware limits.
Limit could be queried using Graphic3d_GraphicDriver::InquireLimit() with Graphic3d_TypeOfLimit_MaxMsaa parameter or using vglinfo command in Draw Harness.
Note that returned limit could be equal to 0, which means no MSAA support.
::RenderResolutionScale should be set to default 1.0 value to use MSAA mode.
In general, MSAA is a compromise between quality and performance.
2 samples configuration doesn’t cost to much but usually provides poor visual result (worse than without MSAA in some cases).
4 samples provides average result, and 8 samples gives best results (some systems might support a higher number of samples).
Graphic3d_RenderingParams::RenderResolutionScale manages resolution used for rendering, which is equal to 1.0 (100%) by default.
Setting this property to values above 1.0 activates super-sampling anti-aliasing (SSAA) mode (e.g. 2.0 for 200% scale).
It is also possible setting property to values below 1.0, which could be used to improve performance on slow graphics hardware (e.g. 0.5 for 50%).
::NbMsaaSamples should be set to default 0 value to use ::RenderResolutionScale.
pload MODELING VISUALIZATION
vinit View1
vbackground -gradient GRAY70 BLACK -gradientMode ELLIPTICAL
# check MSAA limits on specific graphics hardware
set aNbSamples 0
regexp {Max MSAA samples: ([0-9]+)\s} [uplevel 0 vglinfo] res aNbSamples
puts $aNbSamples
# display sample wireframe
box b2 100 100 100
vdisplay b2 -dispMode 0
vfit
# display sample shading
box b1 25 25 25 50 50 50
vdisplay b1 -dispMode 1
# display sample text
vdrawtext t " Label 1.0" -pos 100 50 50 -color GREEN -height 20
# display sample marker
vpoint p 100 50 50
vaspects p -markerType XCIRCLE -markerSize 3 -color BLUE
# render frame at 200% scale
vrenderparams -rendScale 2.00 -msaa 0