Did not sleep ... did not test ... just a wild guess / try ... and i hate vector - "math", its always tryNerror 4 me. maybe it works, maybe iam totally wrong ( the Wood-way ^^ ) with this one grin
Code:
// ------------------------------------------------------------------------------
   trace_mode = IGNORE_ME | IGNORE_PASSABLE | SCAN_TEXTURE; //| USE_POLYGON ?
// ------------------------------------------------------------------------------
   if (c_trace (my.x, vector (my.x, my.y, my.z - 100), trace_mode)) if (HIT_TARGET){
   vec_to_angle   (footRotation, hit.nx);

   VECTOR ttarget;
   vec_set        (ttarget,      vector (0, 90, 0));
   vec_rotate     (ttarget,      footRotation.pan);
   vec_add        (ttarget,      hit.x);
   vec_add        (footRotation, ttarget);
	
   ent_bonerotate (me, "Bip01_L_Foot", vector (0, -ttarget, 0));
   ent_bonerotate (me, "Bip01_R_Foot", vector (0, -ttarget, 0));
	
   vec_set        (pLastSlope, footRotation);
}
// -----------------------------------------------------------------------------
Really no idea if this works ( and if i understood your question right ). if not, just ignore this post ^^

Greets

Acknex umgibt uns...zwischen Dir, mir, dem Stein dort...
"Hey Griswold ... where u gonna put a tree that big ?"
1998 i married my loved wife ... Sheeva from Mortal Kombat, not Evil-Lyn as might have been expected
rayp.flags |= UNTOUCHABLE;