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Let the fog color transition into the sky dome to give a more natural effect

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This commit is contained in:
ehofman
2009-04-11 12:27:05 +00:00
committed by Tim Moore
parent 58f3985567
commit 8537cc9edf
4 changed files with 26 additions and 13 deletions
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27
simgear/scene/sky/dome.cxx
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@@ -189,7 +189,7 @@ SGSkyDome::build( double hscale, double vscale ) {
geom->addPrimitiveSet(domeElements);
geode->addDrawable(geom);
// force a repaint of the sky colors with ugly defaults
repaint(SGVec3f(1, 1, 1), SGVec3f(1, 1, 1), 0.0, 5000.0 );
repaint(SGVec3f(1, 1, 1), SGVec3f(1, 1, 1), SGVec3f(1, 1, 1), 0.0, 5000.0 );
dome_transform = new osg::MatrixTransform;
dome_transform->addChild(geode);
@@ -217,8 +217,8 @@ inline void clampColor(osg::Vec3& color)
// 90 degrees = sun rise/set
// 180 degrees = darkest midnight
bool
SGSkyDome::repaint( const SGVec3f& sky_color, const SGVec3f& fog_color,
double sun_angle, double vis )
SGSkyDome::repaint( const SGVec3f& sun_color, const SGVec3f& sky_color,
const SGVec3f& fog_color, double sun_angle, double vis )
{
SGVec3f outer_param, outer_diff;
SGVec3f middle_param, middle_diff;
@@ -262,26 +262,37 @@ SGSkyDome::repaint( const SGVec3f& sky_color, const SGVec3f& fog_color,
const double saif = sun_angle/SG_PI;
static const SGVec3f blueShift(0.8, 1.0, 1.2);
const SGVec3f skyFogDelta = sky_color - fog_color;
const SGVec3f sunSkyDelta = sun_color - sky_color;
// For now the colors of the upper two rings are linearly
// interpolated between the zenith color and the first horizon
// ring color.
for (int i = 0; i < 7; i++) {
int halfBands = numBands/2;
float ialpha_init = 1.0/halfBands;
float alpha = 1.0, ialpha = 0.0;
for (int i = 0; i < halfBands+1; i++) {
SGVec3f diff = mult(skyFogDelta, blueShift);
diff *= (0.8 + saif - ((6-i)/10));
diff *= (0.8 + saif - ((halfBands-i)/10));
colors(2, i) = (sky_color - upperVisFactor * diff).osg();
colors(3, i) = (sky_color - middleVisFactor * diff + middle_amt).osg();
colors(4, i) = (fog_color + outer_amt).osg();
// Interpolate using distance along dome segment
colors(0, i) = simgear::math::lerp(sky_color.osg(), colors(2, i), .3942);
colors(1, i) = simgear::math::lerp(sky_color.osg(), colors(2, i), .7885);
SGVec3f trans_color;
trans_color[0] = sun_color[0]*alpha + sky_color[0]*ialpha;
trans_color[1] = sun_color[1]*alpha + sky_color[1]*ialpha;
trans_color[2] = sun_color[2]*alpha + sky_color[2]*ialpha;
ialpha += ialpha_init;
alpha -= ialpha_init;
colors(0, i) = simgear::math::lerp(trans_color.osg(), colors(2, i), .3942);
colors(1, i) = simgear::math::lerp(trans_color.osg(), colors(2, i), .7885);
for (int j = 0; j < numRings - 1; ++j)
clampColor(colors(j, i));
outer_amt -= outer_diff;
middle_amt -= middle_diff;
}
printf("\n");
for (int i = 7; i < 12; ++i)
for (int i = halfBands+1; i < numBands; ++i)
for (int j = 0; j < 5; ++j)
colors(j, i) = colors(j, 12 - i);

4
simgear/scene/sky/dome.hxx
View File

@@ -64,8 +64,8 @@ public:
// 0 degrees = high noon
// 90 degrees = sun rise/set
// 180 degrees = darkest midnight
bool repaint( const SGVec3f& sky_color, const SGVec3f& fog_color,
double sun_angle, double vis );
bool repaint( const SGVec3f& sun_color, const SGVec3f& sky_color,
const SGVec3f& fog_color, double sun_angle, double vis );
// reposition the sky at the specified origin and orientation
// lon specifies a rotation about the Z axis

4
simgear/scene/sky/sky.cxx
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@@ -113,8 +113,8 @@ bool SGSky::repaint( const SGSkyColor &sc, const SGEphemeris& eph )
{
if ( effective_visibility > 1000.0 ) {
enable();
dome->repaint( sc.sky_color, sc.fog_color, sc.sun_angle,
effective_visibility );
dome->repaint( sc.adj_sky_color, sc.sky_color, sc.fog_color,
sc.sun_angle, effective_visibility );
stars->repaint( sc.sun_angle, eph.getNumStars(), eph.getStars() );
planets->repaint( sc.sun_angle, eph.getNumPlanets(), eph.getPlanets() );

4
simgear/scene/sky/sky.hxx
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@@ -65,7 +65,9 @@ typedef struct {
} SGSkyState;
typedef struct {
SGVec3f sky_color, fog_color;
SGVec3f sky_color;
SGVec3f adj_sky_color;
SGVec3f fog_color;
SGVec3f cloud_color;
double sun_angle, moon_angle;
} SGSkyColor;