void Atmosphere::raymarchEval(lwpp::VolumetricAccess va)
{
double density = 100.0, falloff = 10.0;
double integstart = 0.0, integend = 100.0;
double minstepsize = 0.01, maxstepsize = 100.0;
double k = 200.0;
double fogclr[ 3 ];
int use_lighting = 1, atmos_type = type;
double dtau, last_dtau, total_tau, rstep, tau, x, y, h, col[ 4 ], trans;
int nsteps = 0; /* record number of integration steps */
double li[ 3 ], last_li[ 3 ];
LWVolumeSample sample; /* differential color & opacity */
// ORIGINALLY LWDVector PP;
lwpp::Point3D PP;
LWMicropol mp;
k *= res;
falloff *= fa;
density /= den;
h = hi - lo;
if ( h == 0 ) return;
/* if using a texture, initialize the micropolygon */
if ( useTxtr ) {
memset( &mp, 0, sizeof( LWMicropol ));
mp.gNorm[ 1 ] = mp.wNorm[ 1 ] = 1.0;
mp.oAxis = mp.wAxis = 1;
mp.oScl[ 0 ] = mp.oScl[ 1 ] = mp.oScl[ 2 ] = 1.0;
}
/* get the fog color */
if ( bck )
{
const double origin[3] = {va.getOrigin().x,va.getOrigin().y, va.getOrigin().z };
backdropinfo->backdrop( time, origin, fogclr );
} else
{
VCPY( fogclr, this->col );
}
/* assume initially that the ray origin is in the fog */
sample.dist = va.getNearClip();
/* below the fog bottom, looking up */
if ( va.getDirection().y > 0 && va.getOrigin().y < lo ) {
y = ( lo - va.getOrigin().y );
x = y / va.getDirection().y;
sample.dist = sqrt( x * x + y * y );
}
/* above the fog top, looking down */
if ( va.getDirection().y < 0 && va.getOrigin().y > hi ) {
y = ( hi - va.getOrigin().y );
x = y / va.getDirection().y;
sample.dist = sqrt( x * x + y * y );
}
/* test if intersection within clipping range */
if ( sample.dist > va.getFarClip() ) return;
// ORIGINALLY
// VADDS3( PP, va.getOrigin(), va.getDirection(), sample.dist );
PP = ((lwpp::Point3D(va.getOrigin()) + lwpp::Vector3D(va.getDirection())) * sample.dist);
y = ( PP.y - lo ) / h;
/* test if outside fog */
if (( y > 1 && va.getDirection().y > 0 ) || ( y < 0 && va.getDirection().y < 0 ))
return;
dtau = density * GADD( va, PP.asLWDVector(), y, falloff, use_lighting, atmos_type, li );
rstep = 1.0 / ( k * dtau + 0.001 );
sample.stride = sample.dist * MAX( MIN( CLAMP( rstep, minstepsize, maxstepsize ),
va.getFarClip() - sample.dist ), 0.0005 );
++nsteps;
total_tau = 0;
while (( sample.dist <= va.getFarClip() )
&& ( total_tau * opa < 300 ) && ( nsteps < 200 )) {
last_dtau = dtau;
VCPY( last_li, li );
// ORIGINALLY
// VADDS3( PP, va.getOrigin(), va.getDirection(), sample.dist );
y = ( upcomp( PP.asLWDVector() ) - lo ) / h;
/* test if outside fog */
if (( y > 1 && va.getDirection().y > 0 ) || ( y < 0 && va.getDirection().y < 0 ))
return;
dtau = density * GADD( va, PP.asLWDVector(), y, falloff, use_lighting, atmos_type, li );
if ( !useTxtr ) {
trans = 0;
VSCL3( col, fogclr, lum );
}
else {
trans = evalTexture( &mp, PP.asLWDVector(), sample.stride, col, txtr );
VSCL( col, lum );
}
if ( trans != 1.0 ) {
tau = 0.5 * sample.stride * ( dtau * ( 1.0 - trans ) + last_dtau );
total_tau += tau;
/* color */
sample.color[ 0 ] = 0.5 * col[ 0 ] * sample.stride
* ( li[ 0 ] * dtau + last_li[ 0 ] * last_dtau );
sample.color[ 1 ] = 0.5 * col[ 1 ] * sample.stride
* ( li[ 1 ] * dtau + last_li[ 1 ] * last_dtau );
sample.color[ 2 ] = 0.5 * col[ 2 ] * sample.stride
* ( li[ 2 ] * dtau + last_li[ 2 ] * last_dtau );
/* opacity */
VSET( sample.opacity, tau * opa );
/* add volumetric sample to the ray */
va.addSample( &sample );
}
/* new stride = f(dist) */
rstep = 1.0 / ( k * dtau + 0.001 );
sample.stride = sample.dist * MAX( MIN( CLAMP( rstep, minstepsize, maxstepsize ),
va.getFarClip() - sample.dist ), 0.0005 );
sample.dist += sample.stride;
nsteps += 1;
}
}
void raymarchEval( const LWVolumeAccess *va, AtmosphereData *dat )
{
double density = 100.0, falloff = 10.0;
double integstart = 0.0, integend = 100.0;
double minstepsize = 0.01, maxstepsize = 100.0;
double k = 200.0;
double fogclr[ 3 ];
int use_lighting = 1, atmos_type = dat->type;
double dtau, last_dtau, total_tau, rstep, tau, x, y, h, col[ 4 ], trans;
int nsteps = 0; /* record number of integration steps */
double li[ 3 ], last_li[ 3 ];
LWVolumeSample sample; /* differential color & opacity */
LWDVector PP;
LWMicropol mp;
k *= dat->res;
falloff *= dat->fa;
density /= dat->den;
h = dat->hi - dat->lo;
if ( h == 0 ) return;
/* if using a texture, initialize the micropolygon */
if ( dat->useTxtr ) {
memset( &mp, 0, sizeof( LWMicropol ));
mp.gNorm[ 1 ] = mp.wNorm[ 1 ] = 1.0;
mp.oAxis = mp.wAxis = 1;
mp.oScl[ 0 ] = mp.oScl[ 1 ] = mp.oScl[ 2 ] = 1.0;
}
/* get the fog color */
if ( dat->bck )
backdropinfo->backdrop( dat->time, va->dir, fogclr );
else
VCPY( fogclr, dat->col );
/* assume initially that the ray origin is in the fog */
sample.dist = va->nearClip;
/* below the fog bottom, looking up */
if ( va->dir[ 1 ] > 0 && va->o[ 1 ] < dat->lo ) {
y = ( dat->lo - va->o[ 1 ] );
x = y / va->dir[ 1 ];
sample.dist = sqrt( x * x + y * y );
}
/* above the fog top, looking down */
if ( va->dir[ 1 ] < 0 && va->o[ 1 ] > dat->hi ) {
y = ( dat->hi - va->o[ 1 ] );
x = y / va->dir[ 1 ];
sample.dist = sqrt( x * x + y * y );
}
/* test if intersection within clipping range */
if ( sample.dist > va->farClip ) return;
VADDS3( PP, va->o, va->dir, sample.dist );
y = ( upcomp( PP ) - dat->lo ) / h;
/* test if outside fog */
if (( y > 1 && va->dir[ 1 ] > 0 ) || ( y < 0 && va->dir[ 1 ] < 0 ))
return;
dtau = density * GADD( va, PP, y, falloff, use_lighting, atmos_type, li );
rstep = 1.0 / ( k * dtau + 0.001 );
sample.stride = sample.dist * MAX( MIN( CLAMP( rstep, minstepsize, maxstepsize ),
va->farClip - sample.dist ), 0.0005 );
++nsteps;
total_tau = 0;
while (( sample.dist <= va->farClip )
&& ( total_tau * dat->opa < 300 ) && ( nsteps < 200 )) {
last_dtau = dtau;
VCPY( last_li, li );
VADDS3( PP, va->o, va->dir, sample.dist );
y = ( upcomp( PP ) - dat->lo ) / h;
/* test if outside fog */
if (( y > 1 && va->dir[ 1 ] > 0 ) || ( y < 0 && va->dir[ 1 ] < 0 ))
return;
dtau = density * GADD( va, PP, y, falloff, use_lighting, atmos_type, li );
if ( !dat->useTxtr ) {
trans = 0;
VSCL3( col, fogclr, dat->lum );
}
else {
trans = evalTexture( &mp, PP, sample.stride, col, dat->txtr );
VSCL( col, dat->lum );
}
if ( trans != 1.0 ) {
tau = 0.5 * sample.stride * ( dtau * ( 1.0 - trans ) + last_dtau );
total_tau += tau;
/* color */
sample.color[ 0 ] = 0.5 * col[ 0 ] * sample.stride
* ( li[ 0 ] * dtau + last_li[ 0 ] * last_dtau );
sample.color[ 1 ] = 0.5 * col[ 1 ] * sample.stride
* ( li[ 1 ] * dtau + last_li[ 1 ] * last_dtau );
sample.color[ 2 ] = 0.5 * col[ 2 ] * sample.stride
* ( li[ 2 ] * dtau + last_li[ 2 ] * last_dtau );
/* opacity */
VSET( sample.opacity, tau * dat->opa );
/* add volumetric sample to the ray */
va->addSample( va->ray, &sample );
}
/* new stride = f(dist) */
rstep = 1.0 / ( k * dtau + 0.001 );
sample.stride = sample.dist * MAX( MIN( CLAMP( rstep, minstepsize, maxstepsize ),
va->farClip - sample.dist ), 0.0005 );
sample.dist += sample.stride;
nsteps += 1;
}
}