This one is a weird one.

Say I have an armorstand and I do:

/entitydata @e[type=ArmorStand]

{Motion:[1,0,0]}

The armorstand will move with a motion of 1 in the x-axis.

Now if I do
/entitydata @e[type=ArmorStand]

{NoGravity:1}

then
/entitydata @e[type=ArmorStand]

{Motion:[1,0,0]}

the armorstand doesn't move at all. This is the case in all directions, x,y and z.

By testing for the armorstands data using
/entitydata @e[type=ArmorStand] {}
immediately after setting the motion, you can see the motion is still there. But the armorstand isn't moving.

------------------------------------------------------------------------------------------------

Furthermore if I have a cow and I do

/entitydata @e[type=Cow]

{Motion:[1,0,0]}

The cow will move with a motion of 1 in the x-axis.

Now if I do
/entitydata @e[type=Cow]

{NoAI:1}

then
/entitydata @e[type=Cow]

{Motion:[1,0,0]}

The cow doesn't move at all. This is the case in all directions, x,y and z.

By testing for the cow's data using
/entitydata @e[type=Cow] {}
immediately after setting the motion, you can see the motion is still there. But the cow just isn't moving.

------------------------------------------------------------------------------------------------

What I expected:

Ideally one would have the gravity code only acting on those with the NoGravity:0 tag instead of ignoring the velocity all together.

The NoAI tag should just ignore the AI code and have nothing to do with the velocity of the entities.

If this change was added I'd also suggest adding a NoVelocity tag that ignores all velocities (like the current NoAI and NoGravity tags) as this is still useful in certain situations