Night Vision Simulation of Drive Simulator Based on OpenGVS4.5 - Advances in Image and Graphics Technologies - page 260

GV_lsr_set_attenuation( spotlight , GL_CONSTANT_ATTENUATION, kc );
GV_lsr_set_attenuation( spotlight , GL_LINEAR_ATTENUATION, kl );
GV_lsr_set_attenuation( spotlight , GL_QUADRATIC_ATTENUATION, kq );
GV_lsr_set_spot_exponent( spotlight , attenuation );
2.4 Pixel-level point light
Spotlight is a good model for analog lights and headlight. While the series of
OpenGVS real-time visual model-driven engine spotlight had bugs, such as rendering
by the presence of surface and limited number. For this purpose, OpenGVS4.5 pro-
vided a Pixel-level point light. The model had the same properties with spotlights
model which also allowed the user to set the different positions as required, the direc-
tion, the taper angle, the degree of attenuation and the irradiation distance in order to
generate the pixel-rendering of lighting effects, and allowed the user to modify in real
time according to the vehicle motion state. However, pixel-level point source model
requires hardware support. Created as follows:
GVU_Plsr spotlight = NULL;
G_Boolean plsr_support ;
GVU_plsr_inq_supported( &plsr_support ) ; // Asked hardware support
if (!plsr_support) return NULL;
GVU_plsr_create( &spotlight);

3 Night Vision Effects simulation

Night training simulation needs the night vision of simulator. It's easy in the
OpenGVS4.5 because the infinity light source in OpenGVS4.5 is very similar to the
real world of the sun - as long as the proper direction vector set of infinity light can
simulate dawn, sunrise, noon , evening, midnight, etc. We would like to indicate that in
order to achieve these effects, the illumination attribute of all terrains, features, and the
entity model must be turned on.

4 Night Observation Effect Simulation

Another problem that needed to be solved was the simulation of a variety of observation
equipment in night training simulation. The existing observation equipment varied, the
simulation methods were not the same with different principles and observation effect.

4.1 Headlight Illumination Simulation

Headlight illumination simulation could use OpenGVS4.5 unique pixel-level point source.

4.1.1 Creation and Initialization of Pixel-Level Point Light Sources
As mentioned earlier, as long as the hardware supports (currently this is not a problem,
most of the high-end graphics cards are supported), one can use the pixel-level point
source to simulate lighting effects. Properties of pixel-level point source model was the