code: protected void estimateP3P(int excluded) {
  
  		// the point used to check the solutions is the last one
  		inputP3P.clear();
  		for( int i = 0; i < 4; i++ ) {
  			if( i != excluded ) {
  				inputP3P.add( points.get(i) );
  			}
  		}
  
  		// initial estimate for the pose
  		solutions.reset();
  		if( !p3p.process(inputP3P,solutions) ) {
  //			System.err.println("PIP Failed!?! That's weird");
  			return;
  		}
  
  
  		for (int i = 0; i < solutions.size; i++) {
  			double error = computeErrors(solutions.get(i));
  
  			// see if it's better and it should save the results
  			if( error < bestError ) {
  				bestError = error;
  				bestPose.set(solutions.get(i));
  			}
  		}
  
  	}
docs: Estimates the pose using P3P from 3 out of 4 points.  Then use all 4 to pick the best solution
  
  @param excluded which corner to exclude and use to check the answers from the others