Flipping cards

[edmundrw]

Greetings,fellow members! I need help with my school project. My teacher don't understand this matter very well.
So my problem is the card I used always go upwards,despite the gravity I give. What does make the card go upwards? Any help is appreciated,I'm still new at this.
This is my code :
#define dDOUBLE
#include<ode\ode.h>
#include<SDL.h>
#include"C:\Users\UMUM\Desktop\odemeshstl\drawing.h"
#include"C:\Users\UMUM\Desktop\odemeshstl\bodydrawer.h"
#include<cstdlib>
#define NKONTAKMAKS 32
#define WWIDTH 800
#define WHEIGHT 600
#define HWIDTH 11
#define HHEIGHT 19
using namespace std;
dWorldID w;
dGeomID gb2,glantai;
dBodyID b2;
dJointGroupID kontakgroup;
dSpaceID ruang;

static void kontakcallback(void *data, dGeomID g1,dGeomID g2){
dBodyID b3,b4;
b3 = dGeomGetBody(g1);
b4 = dGeomGetBody(g2);
/*
//ambil posisi body
dReal r1[3], r2[3];
for(int i=0;i<3;i++){
if(b1) r1[i]=dBodyGetPosition(b1)[i];
if(b2) r2[i]=dBodyGetPosition(b2)[i];
}
*/
dContact kontak[NKONTAKMAKS];
int n = dCollide(g1,g2,NKONTAKMAKS,&(kontak[0].geom), sizeof(dContact));
if(n>0){
//cout<<"kontak:"<<n<<endl;
for(int i=0;i<n;i++){
/* contact[i].surface.mode = dContactBounce | dContactSoftCFM;
contact[i].surface.mu = dInfinity;
contact[i].surface.mu2 = 0;
contact[i].surface.bounce = 0.1;
contact[i].surface.bounce_vel = 0.1;
contact[i].surface.soft_cfm = 0.01;
*/
kontak[i].surface.mu = 0.3;
kontak[i].surface.bounce = 0;
kontak[i].surface.bounce_vel = 0;
kontak[i].surface.soft_cfm = 0.1;
kontak[i].surface.soft_erp = 0.1;
kontak[i].surface.mode = dContactBounce | dContactSoftCFM | dContactSoftERP | dContactApprox1_N;
dJointID c = dJointCreateContact(w,kontakgroup,&(kontak[i]));
dJointAttach(c,b3,b4);
}
}
}
int main(int argc,char *argv[])
{
SDL_Window *window;
SDL_Surface *fontsurf=NULL;
SDL_Surface *mainsurf=NULL;
SDL_Event E;
SDL_Init(SDL_INIT_VIDEO);
window = SDL_CreateWindow("Test Mesh STL",SDL_WINDOWPOS_UNDEFINED,SDL_WINDOWPOS_UNDEFINED,WWIDTH,WHEIGHT,0);
mainsurf=SDL_GetWindowSurface(window);
bersih(mainsurf, SDL_MapRGB(mainsurf->format,0,0,0));

SDL_FillRect(mainsurf, 0, 0x008000FF);
//fontsurf=SDL_LoadBMP("font.bmp");
//if(fontsurf==NULL) return 1;
dInitODE();

dReal x,y,z,ax,ay,az,angle;
// dWorldID w;
w = dWorldCreate();
dWorldSetGravity(w,0,0,-9.81);
//dWorldSetContactSurfaceLayer(w,0.0005);
// dBodyID b2;
//dGeomID gb2;
dJointGroupID kontakgroup;
kontakgroup = dJointGroupCreate(0);
dTriMeshDataID mesh1;
// dSpaceID ruang;
ruang = dSimpleSpaceCreate(0);

dReal sudut,xs,ys,zs;
dQuaternion q1;
b2=dBodyCreate(w);
dMass m2;
dMassSetBoxTotal(&m2, 0.1,0.087,0.0625,0.0003);
dBodySetMass(b2, &m2);
//gb2 = dCreateBox(ruang,0.087,0.0625,0.00003);
mesh1 = dGeomTriMeshDataCreate();
stlreader s1("kartu6.stl");
//s1.geserketengah();
//s1.geserkeorigin();
s1.jadikantrimesh(mesh1);
gb2 = dCreateTriMesh(ruang, mesh1,0,0,0);
dGeomSetBody(gb2, b2);

dBodySetPosition(b2,0,0,0.0003);
//dBodySetLinearVel(b2,0,0,1.5);
// dQFromAxisAndAngle (q1,0.1,0.1,0.1,0);
//dBodySetQuaternion(b2,q1);
dBodySetAngularVel(b2,0,50,0);
glantai = dCreatePlane(ruang,0,0,1,0);
bodystlconnector bodystl1(&s1, b2);
bodydrawer drawer(mainsurf);
drawer.setorigin(WWIDTH/2, WHEIGHT*3/4);
drawer.setwarna(255,0,0);
drawer.setskala(1000);
drawer.setproyeksi(PROYEKSI_XZ);
dReal deltat=0.01;
// dReal x,y,z;
//ofstream Morison_File ("linear_wave_loading.csv");
//Morison_File <<"x"<<","<<"y"<<","<<"z"<<","<<"sudut"<<","<<"xs"<<","<<"ys"<<","<<"zs"<< endl;
//for(int i=1;i<=300;i++){


int running=1;
while(running){dSpaceCollide(ruang,0,&kontakcallback);
//dWorldSetGravity(w,0,0,-9.81);
dWorldQuickStep(w, deltat);

dJointGroupEmpty(kontakgroup);
// drawer.tampiltitik(b2);
bersih(mainsurf, SDL_MapRGB(mainsurf->format,0,0,0));
drawer.tampilstl(&bodystl1);
garis(mainsurf,0,450,800,450,0x00800000);
if(SDL_PollEvent(&E)){
switch(E.type)
{
case SDL_KEYDOWN:
switch(E.key.keysym.sym)
{
case SDLK_RETURN:
running=0;
break;
default:;
}
}
}
// bersih(mainsurf,SDL_MapRGB(mainsurf->format,0,0,0));
//tulis("spasi untuk reset, enter untuk keluar",mainsurf,0,0,fontsurf);
// drawer.tampilstl(&bodystl1);
/*
float x2 = dBodyGetPosition(b2)[0];
float y2 = dBodyGetPosition(b2)[2];
lingkaran(mainsurf,x2*10+WWIDTH/2, WHEIGHT-y2*10,40,SDL_MapRGB(mainsurf->format,0,255,255));
*/
//drawer.tampillingkaran(b2,4);
SDL_UpdateWindowSurface(window);
//SDL_Delay(50);

}

return 0;
}

[eraggo]

Have you realized that SDL goes "opposite way". That being top left corner is 0,0 and bottom right is window height and width?

Flipping gravity from -9.81 to 9.81 should fix something if it is not correctly handled on physics engine which is not seen on the code. If there is compensation on the physics side already (-1)*(-1)=1 and that makes issue

[edmundrw]

Thank you for your response! I tried that,and it doesn't solve the problem. When I set the angular velocity to 0,0,0 , The card isn't just lying on the ground. It did at first,but then it's flying. I tried to modify the erp and cfm part, and found that if I set the erp to zero then it wouldn't fly,but it wouldn't flip if I set the angular velocity either.
If I set the erp to 0.x(say,0.5) the card would flip but then bounce indefinitely. I also tried to disable erp and cfm,enabling only bounce,but this still happens. Also tried to disable bounce but enable erp and cfm,still the same. Is there any workaround? TIA!

[edmundrw]

Update - Just noticed there are double lines. Solved.