Mdl* mdl = mdl_create ();
mdl_addbone(mdl, mdl_bonecreate(NULL, NULL, NULL));
mdl_addbone(mdl, mdl_bonecreate(NULL, vector(50,0,0), mdl_getbone(mdl, 0)));
mdl_addbone(mdl, mdl_bonecreate(NULL, vector(25,25,25), mdl_getbone(mdl, 1)));

MdlCollection* collection = mdl_collectioncreate();

int i, radius = 50, segments = 150;
for (i = 0; i < segments; i++)
{
    VECTOR pos, angle;
    
    var a = i * (360 / segments);
    vec_set(&angle, vector(a, sin(a) * 25, 0));
    
    vec_set(&pos, vector(radius, 0, 0));
    vec_rotate(&pos, &angle);
    
    MdlInstance* instance = mdl_instancecreate(mdl, &pos, &angle, NULL, 1);
    mdl_collectionaddinstance(collection, instance);
}

Mdl* mdlCollection = mdl_collectioncreatemdl(collection);
mdl_save(mdlCollection, "mdlCollection2.mdl");