Overlapping S/C in OpenGL during close-range rendezvous simulation

[thjpark]

Howdy!

I'm trying to simulate two S/C that are operating at close proximity (< 100 m). The way I've set up the simulation is to create two reference orbits and two spacecraft that each refers to the respective reference orbit files.

I've verified that PosN of both S/C behave as expected, as the magnitude of the difference of PosN vectors of two S/C show correct ranges of values. However, on the OpenGL front end, the two S/C appears completely overlapped at the exact same spot throughout the simulation. Would you be able to tell what the potential issue might be?

I guess I can also set the offsets under the Orbit Parameters of the SC_*.txt files, but I'm still curious how the above scenario might work.

Thanks in advance,
Jeff

[thjpark]

In case anyone is wondering, under 42gl.c, FindModelMatrices function, use

for(i=0;i<3;i++) pbn[i] = (S->PosN[i] - S0->PosN[i]) + B->pn[i] - pcmn[i]; where struct SCType *S0 = &SC[0]

instead of

for(i=0;i<3;i++) pbn[i] = S->PosR[i] + B->pn[i] - pcmn[i];

since PosR is zero unless the offsets are explicitly set in the SC_*.txt files.