We compute a 5-dimensional scalar field given by the interaction of energy between a small ligand and a large receptor molecule with three translational degrees of freedom and two rotational degrees of freedom of the ligand. This display is performed directly by a projection from 5D space to 2D space without a slicing/isocontouring stage. The information contained in the dataset is preserved in its globality.
Consider the coordinate system where one of the axis (representing one of the rotational degrees of freedom) is much longer than the others. This gives the field depicted on the right-top where in red shows the regions of negative potential (the ligand is free to move in a region of attraction from the receptor.)In blue are the regions of high positive potential (the ligand collides with the receptor.) The green color shows the region of free movement 0-potential regions. From the picture (viewed from one of the rotational degrees of freedom) it is clear that low or high angles (large red spots) are more favorable for binding molecules since the ligand has large regions of movement.  Removing all the color but the red as in the figure on the left-bottom  you see how these two  regions are connected by a narrow tunnel.
To get better understanding we need to explore different view of the dataset. Changing the axis as in the picture on the left we stretch one  of translational degrees of freedom. This give rise to the view on the left-top where we can see that the two large regions are in turn divided each into two. On the bottom right one can notice an interesting site in green where the ligand can move along the interface with the receptor without being subject to a repulsion force. Again removing all the color but the red we can see clearly that in the central region  there are no red spot meaning it is completely repulsive (see left-bottom image). Note that this kind of check by partial color removal is necessary because some red spot might be hiddent in the blue region