<story><title>Rotate the world</title><url>http://www.jasondavies.com/maps/rotate/</url></story><parent_chain><item><author>BitMastro</author><text>This is just my personal preference, but I believe the naive implementation is miles ahead of the improved ones.&lt;p&gt;The improved version needs at least two movements to go to the other side of the world, doesn&amp;#x27;t follow the rotation if the cursor is too fast and worse than all, performs a gamma rotation for each non-equatorial point of the sphere.&lt;p&gt;Since we have two degrees of freedom on the screen, I expect to use them to drive the two most used rotations, and maybe have another control for the roll. In addition, we are used to have maps with North pointing up (and sometimes pointing South), so the roll is almost never used.</text></item></parent_chain><comment><author>kcorbitt</author><text>Another nice attribute the naive implementation has is path independence.  If I grab part of the globe and release it somewhere else I expect those two coordinates to determine the transform.  With the non-naive implementation I can get completely different results depending on how I wiggle my mouse on the way.  It&amp;#x27;s true that this gives me more flexibility, but I don&amp;#x27;t know... it just doesn&amp;#x27;t feel right to me.  Google Earth does it that way too, and it has always bothered me.  If I move more than a few degrees on the map I find myself either wildly gyrating my mouse to try to get back into a recognizable north-up orientation or simply clicking the compass rose to have it set things right automatically.</text></comment>
<story><title>Rotate the world</title><url>http://www.jasondavies.com/maps/rotate/</url></story><parent_chain><item><author>BitMastro</author><text>This is just my personal preference, but I believe the naive implementation is miles ahead of the improved ones.&lt;p&gt;The improved version needs at least two movements to go to the other side of the world, doesn&amp;#x27;t follow the rotation if the cursor is too fast and worse than all, performs a gamma rotation for each non-equatorial point of the sphere.&lt;p&gt;Since we have two degrees of freedom on the screen, I expect to use them to drive the two most used rotations, and maybe have another control for the roll. In addition, we are used to have maps with North pointing up (and sometimes pointing South), so the roll is almost never used.</text></item></parent_chain><comment><author>cousin_it</author><text>Agreed. You could slightly improve the naive implementation by restricting the north-south rotation so you can&amp;#x27;t go beyond either pole, so north always stays up. It&amp;#x27;s not just for the Earth either, I&amp;#x27;m now working on a 3D object editor and decided on the naive implementation there as well, because when you&amp;#x27;re sculpting a chair, it&amp;#x27;s annoying if up doesn&amp;#x27;t stay up.</text></comment>