Changed condition to set pKFm

[ethanseq]

The solution proposed for #13 (comment) involved switching bDifferentKFs to be initially set to true and would then be switched to false if vpKeyFrameMatchedMp was empty. However, this technically isn't correct as an empty vpKeyFrameMatchedMp insinuates that it is a different key frame. Thus,

MORB_SLAM/src/Sim3Solver.cc

Line 84 in f3c8f3c

if(!bDifferentKFs)

was changed to only set pKFm if it isn't a different frame. Otherwise, the default pKFm value of pKF2 is used instead.

[ethanseq]

Additional Clarification:

MORB_SLAM/src/Sim3Solver.cc

Lines 40 to 44 in f3c8f3c

	bool bDifferentKFs = false;
	if(vpKeyFrameMatchedMP.empty())
	{
	bDifferentKFs = true;
	vpKeyFrameMatchedMP = vector<KeyFrame*>(vpMatched12.size(), pKF2);

If vpKeyFrameMatchedMP is empty, we determine that we have different keyframes and set bDifferentKFs to true while also setting vpKeyFrameMatchedMP to pKF2 which is the keyframe with the most BoW matches.

MORB_SLAM/src/Sim3Solver.cc

Line 70 in f3c8f3c

KeyFrame* pKFm = pKF2; //Default variable

The default for pKFm is set to pKF2. However, we can see in

MORB_SLAM/src/Sim3Solver.cc

Lines 84 to 85 in f3c8f3c

	if(!bDifferentKFs)
	pKFm = vpKeyFrameMatchedMP[i1];

that pKFm is only set if bDifferentKFs is true, which is reduntant since it is already set the pKF2 as the default. Therefore, the condition needs to be changed in order to make sure that pKFm when bDifferentKFs is false.

[Ryan-Red]

Tried and did not produce any noticeable results