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fixed small glitch multiplying nodemass twice (thanks ton)

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claened up sbObjectStep(...) to follow 'time step rules'
added really care for framerate in scene
renamed arguments in softbody_calc_forces(...); and softbody_apply_forces(...); for better reading
fixed particle integration to be ODE solver compatible
This commit is contained in:
Jens Ole Wund
2005-04-05 20:28:32 +00:00
parent 7bb97ac815
commit 331c25dda4
3 changed files with 71 additions and 50 deletions
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4
source/blender/blenkernel/BKE_effect.h
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@@ -62,7 +62,9 @@ void calc_wave_deform(struct WaveEff *wav, float ctime, float *co);
int object_wave(struct Object *ob);
/* particle deflector */
void pdDoEffector(float *opco, float *force, float *speed, float cur_time, unsigned int par_layer);
#define PE_WIND_AS_SPEED 0x00000001
void pdDoEffector(float *opco, float *force, float *speed, float cur_time, unsigned int par_layer,unsigned int flags);
int pdDoDeflection(float opco[3], float npco[3], float opno[3],
float npno[3], float life, float force[3], int def_depth,
float cur_time, unsigned int par_layer, int *last_object,

13
source/blender/blenkernel/intern/effect.c
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@@ -389,7 +389,7 @@ static int linetriangle(float p1[3], float p2[3], float v0[3], float v1[3], floa
par_layer = layer the caller is in
*/
void pdDoEffector(float *opco, float *force, float *speed, float cur_time, unsigned int par_layer)
void pdDoEffector(float *opco, float *force, float *speed, float cur_time, unsigned int par_layer,unsigned int flags)
{
/*
Modifies the force on a particle according to its
@@ -459,11 +459,16 @@ void pdDoEffector(float *opco, float *force, float *speed, float cur_time, unsig
/* the force is not too big */
if (distance < 0.001) distance = 0.001f;
f_force = (force_val)*(1/(1000 * (float)pow((double)distance, (double)ffall_val)));
if(flags &&PE_WIND_AS_SPEED){
speed[0] -= (force_vec[0] * f_force );
speed[1] -= (force_vec[1] * f_force );
speed[2] -= (force_vec[2] * f_force );
}
else{
force[0] += force_vec[0]*f_force;
force[1] += force_vec[1]*f_force;
force[2] += force_vec[2]*f_force;
}
}
else if(pd->forcefield == PFIELD_FORCE) {
@@ -891,7 +896,7 @@ void make_particle_keys(int depth, int nr, PartEff *paf, Particle *part, float *
/* Check force field */
cur_time = pa->time;
pdDoEffector(opco, new_force, new_speed, cur_time, par_layer);
pdDoEffector(opco, new_force, new_speed, cur_time, par_layer,0);
/* new location */
pa->co[0]= opa->co[0] + deltalife * (opa->no[0] + new_speed[0] + 0.5f*new_force[0]);

104
source/blender/blenkernel/intern/softbody.c
View File

@@ -88,7 +88,6 @@ extern int get_defgroup_num (Object *ob, bDeformGroup *dg);
#define HEUNWARNLIMIT 1 // 50 would be fine i think for detecting severe *stiff* stuff
float SoftHeunTol = 1.0f; // humm .. this should be calculated from sb parameters and sizes
float steptime = 1.0f/25.0f; // translate framerate to *real* time
float rescale_grav_to_framerate = 1.0f; // since unit of g is [m/sec^2] we need translation from frames to physics time
float rescale_friction_to_framerate = 1.0f; // since unit of drag is [kg/sec] we need translation from frames to physics time
@@ -286,7 +285,7 @@ static int is_there_deflection(unsigned int layer)
}
static void softbody_calc_forces(Object *ob, float dtime)
static void softbody_calc_forces(Object *ob, float forcetime)
{
SoftBody *sb= ob->soft; // is supposed to be there
BodyPoint *bp;
@@ -300,10 +299,9 @@ static void softbody_calc_forces(Object *ob, float dtime)
bp->force[0]= bp->force[1]= bp->force[2]= 0.0;
}
gravity = sb->grav * rescale_grav_to_framerate;
/* check! */
do_effector= is_there_deflection(ob->lay);
gravity = sb->nodemass * sb->grav * rescale_grav_to_framerate;
iks = 1.0f/(1.0f-sb->inspring)-1.0f ;/* inner spring constants function */
bproot= sb->bpoint; /* need this for proper spring addressing */
@@ -325,7 +323,7 @@ static void softbody_calc_forces(Object *ob, float dtime)
VecSubf(velgoal,bp->origS, bp->origE);
kd = sb->goalfrict * rescale_friction_to_framerate ;
if (dtime > 0.0 ) { // make sure friction does not become rocket motor on time reversal
if (forcetime > 0.0 ) { // make sure friction does not become rocket motor on time reversal
bp->force[0]-= kd * (velgoal[0] + bp->vec[0]);
bp->force[1]-= kd * (velgoal[1] + bp->vec[1]);
bp->force[2]-= kd * (velgoal[2] + bp->vec[2]);
@@ -341,33 +339,46 @@ static void softbody_calc_forces(Object *ob, float dtime)
/* gravitation */
bp->force[2]-= gravity*sb->nodemass; /* individual mass of node here */
/* friction in media */
kd= sb->mediafrict* rescale_friction_to_framerate;
/* assume it to be proportional to actual velocity */
bp->force[0]-= bp->vec[0]*kd;
bp->force[1]-= bp->vec[1]*kd;
bp->force[2]-= bp->vec[2]*kd;
/* friction in media done */
/* particle field & vortex */
if(do_effector & USES_FIELD) {
float force[3]= {0.0f, 0.0f, 0.0f};
float speed[3]= {0.0f, 0.0f, 0.0f};
pdDoEffector(bp->pos, force, speed, (float)G.scene->r.cfra, ob->lay,PE_WIND_AS_SPEED);
// note: now we have wind as motion of media, so we can do anisotropic stuff here,
// if we had vertex normals here(BM)
/* apply force */
// VecMulf(force, rescale_grav_to_framerate); <- didn't work, made value far too low!
VecMulf(force,25.0f* rescale_friction_to_framerate);
VECADD(bp->force, bp->force, force);
/* apply speed. note; deflector can give 'speed' only.... */
/* nooo! we never alter free variables :bp->vec bp->pos in here !
* this will ruin adative stepsize AHA heun! (BM)
* VECADD(bp->vec, bp->vec, speed);
*/
/* friction in moving media */
kd= sb->mediafrict* rescale_friction_to_framerate;
bp->force[0] -= kd * (bp->vec[0] - speed[0]/rescale_friction_to_framerate);
bp->force[1] -= kd * (bp->vec[1] - speed[1]/rescale_friction_to_framerate);
bp->force[2] -= kd * (bp->vec[2] - speed[2]/rescale_friction_to_framerate);
/* now we'll have nice centrifugal effect for vortex */
}
else {
/* friction in media (not) moving*/
kd= sb->mediafrict* rescale_friction_to_framerate;
/* assume it to be proportional to actual velocity */
bp->force[0]-= bp->vec[0]*kd;
bp->force[1]-= bp->vec[1]*kd;
bp->force[2]-= bp->vec[2]*kd;
/* friction in media done */
}
/*other forces*/
/* this is the place where other forces can be added
yes, constraints and collision stuff should go here too (read baraff papers on that!)
*/
/* particle field & deflectors */
if(do_effector & USES_FIELD) {
float force[3]= {0.0f, 0.0f, 0.0f};
float speed[3]= {0.0f, 0.0f, 0.0f};
pdDoEffector(bp->pos, force, speed, (float)G.scene->r.cfra, ob->lay);
/* apply force */
// VecMulf(force, rescale_grav_to_framerate); <- didn't work, made value far too low!
VECADD(bp->force, bp->force, force);
/* apply speed. note; deflector can give 'speed' only.... */
VecMulf(speed, rescale_grav_to_framerate);
VECADD(bp->vec, bp->vec, speed);
}
#if 0
/* copied from particles... doesn't work really! */
if(do_effector & USES_DEFLECT) {
@@ -492,7 +503,7 @@ static void softbody_calc_forces(Object *ob, float dtime)
}
}
static void softbody_apply_forces(Object *ob, float dtime, int mode, float *err)
static void softbody_apply_forces(Object *ob, float forcetime, int mode, float *err)
{
/* time evolution */
/* actually does an explicit euler step mode == 0 */
@@ -504,13 +515,14 @@ static void softbody_apply_forces(Object *ob, float dtime, int mode, float *err)
float maxerr = 0.0;
int a;
if (sb->nodemass > 0.09999f) timeovermass = dtime/sb->nodemass;
else timeovermass = dtime/0.09999f;
if (sb->nodemass > 0.09999f) timeovermass = forcetime/sb->nodemass;
else timeovermass = forcetime/0.09999f;
for(a=sb->totpoint, bp= sb->bpoint; a>0; a--, bp++) {
if(bp->goal < SOFTGOALSNAP){
/* so here is dv/dt = a = sum(F_springs)/m + gravitation + some friction forces */
/* so here is (v)' = a(cceleration) = sum(F_springs)/m + gravitation + some friction forces + more forces*/
/* the ( ... )' operator denotes derivate respective time
/* the euler step for velocity then becomes */
/* v(t + dt) = v(t) + a(t) * dt */
bp->force[0]*= timeovermass; /* individual mass of node here */
@@ -534,14 +546,14 @@ static void softbody_apply_forces(Object *ob, float dtime, int mode, float *err)
}
else {VECADD(bp->vec, bp->vec, bp->force);}
/* so here is dx/dt = v */
/* so here is (x)'= v(elocity) */
/* the euler step for location then becomes */
/* x(t + dt) = x(t) + v(t) * dt */
VECCOPY(dx,bp->vec);
dx[0]*=dtime ;
dx[1]*=dtime ;
dx[2]*=dtime ;
dx[0]*=forcetime ;
dx[1]*=forcetime ;
dx[2]*=forcetime ;
/* again some nasty if's to have heun in here too */
if (mode ==1){
@@ -1074,26 +1086,27 @@ void sbObjectStep(Object *ob, float framenr)
/* checking time: */
ctime= bsystem_time(ob, NULL, framenr, 0.0);
softbody_scale_time(steptime); // translate frames/sec and lenghts unit to SI system
softbody_scale_time(1.0f/G.scene->r.frs_sec); // translate frames/sec and lenghts unit to SI system
dtime= ctime - sb->ctime;
// dtime= ABS(dtime); no no we want to go back in time with IPOs
timescale = (int)(sb->rklimit * ABS(dtime));
// bail out for negative or for large steps
if(dtime<0.0 || dtime >= 9.9*G.scene->r.framelen) {
if(dtime<0.0 || dtime >= 9.9*G.scene->r.framelen) { // note: what is G.scene->r.framelen for ? (BM)
sbObjectReset(ob);
return;
}
/* the simulator */
if(ABS(dtime) > 0.0) { // note: what does this mean now? (ton)
if(dtime > 0.0) { // note: what does this mean now? (ton)
//answer (BM) :
//dtime is still in [frames]
//we made sure dtime is >= 0.0
//but still need to handle dtime == 0.0 -> just return sb as is, just to be nice
object_update_softbody(ob);
if (TRUE) { // RSOL1 always true now (ton)
/* special case of 2nd order Runge-Kutta type AKA Heun */
float timedone =0.0;
/* counter for emergency brake
float timedone =0.0; // how far did we get without violating error condition
/* loops = counter for emergency brake
* we don't want to lock up the system if physics fail
*/
int loops =0 ;
@@ -1102,7 +1115,7 @@ void sbObjectStep(Object *ob, float framenr)
forcetime = dtime; /* hope for integrating in one step */
while ( (ABS(timedone) < ABS(dtime)) && (loops < 2000) )
{
if (ABS(dtime) > 3.0 ){
if (ABS(dtime) > 9.0 ){
if(G.f & G_DEBUG) printf("SB_STEPSIZE \n");
break; // sorry but i must assume goal movement can't be interpolated any more
}
@@ -1150,6 +1163,7 @@ void sbObjectStep(Object *ob, float framenr)
// loop n times so that n*h = duration of one frame := 1
// x(t+h) = x(t) + h*v(t);
// v(t+h) = v(t) + h*f(x(t),t);
timescale = (int)(sb->rklimit * ABS(dtime));
for(t=1 ; t <= timescale; t++) {
if (ABS(dtime) > 15 ) break;
@@ -1188,7 +1202,7 @@ void sbObjectStep(Object *ob, float framenr)
} // if(ABS(dtime) > 0.0)
else {
// rule : you have asked for the current state of the softobject
// since dtime= ctime - ob->soft->ctime;
// since dtime= ctime - ob->soft->ctime== 0.0;
// and we were not notifified about any other time changes
// so here it is !
softbody_to_object(ob);