Motion vectors shouldn't generally be added together. You don't describe a use case, so I'm thinking of a motion actuator per motion key. However, pressing forward + sideward would then result in an approximately 1.4x (square root of 2) multiplication of your velocity.

Motion vectors shouldn't generally be added together.

Why not?

You don't describe a use case, so I'm thinking of a motion actuator per motion key.

I have describe a use case in the summary (walking/running speed).
New example:

• First actuator (W key) Y + 0.004 normal forward motion = speed 0.004
• First actuator (W key) Y + 0.004 + second actuator (W + left shift) Y + 0.004 active = running speed 0.008

However, pressing forward + sideward would then result in an approximately 1.4x (square root of 2) multiplication of your velocity.

No, this patch don't change the actual behaviour of the add button, It only fix the behaviour that actually it is not possible to add two motion in the same direction.
It does not slow down (approximately 1.4x square root of 2) if you move forward and sidewards at the same time.
We only sum the local vectors, the rest will be done in the Bullet engine.
ACT1 [0.0, 0.004, 0.0] + ACT2 [0.0, 0.004, 0.0] + ACT3 [0.004, 0.0, 0.0] = [0.004, 0.008, 0.0]

I use the same test file in T36703

In D1228#23742, @Thomas Szepe (hg1) wrote:

Motion vectors shouldn't generally be added together.

Why not?

Because of these reasons: http://tvtropes.org/pmwiki/pmwiki.php/Main/DiagonalSpeedBoost

I have describe a use case in the summary (walking/running speed).
New example:

• First actuator (W key) Y + 0.004 normal forward motion = speed 0.004
• First actuator (W key) Y + 0.004 + second actuator (W + left shift) Y + 0.004 active = running speed 0.008

I agree that we should support different walking speeds, and that "add" should, indeed, add the motions.

No, this patch don't change the actual behaviour of the add button, It only fix the behaviour that actually it is not possible to add two motion in the same direction.
It does not slow down (approximately 1.4x square root of 2) if you move forward and sidewards at the same time.

I didn't mean a slowdown, but rather a speedup. If your walking speed is 1 m/sec, you could walk straight ahead with velocity (0, 1, 0) or straight right with velocity (1, 0, 0). If you were to add those two together, you'd move with velocity (1, 1, 0), which represents a speed of 1.4 m/sec.

I didn't mean a slowdown, but rather a speedup. If your walking speed is 1 m/sec, you could walk straight ahead with velocity (0, 1, 0) or straight right with velocity (1, 0, 0). If you were to add those two together, you'd move with velocity (1, 1, 0), which represents a speed of 1.4 m/sec.

Yes you are right, was my fault. I should think before I write.

Test file for diagonal movement.

Actual my solution is also not good. Because it only works with two actuators.
But also the original version is working wrong. Because the movement speed is different if the left and forward speed is different. So the character moves with the speed which actuator was activated first. So if you activate first forward and then left, the movement speed is different to when you activate first left and then forward.

I think it is better to max out the speed and always move 45° angel forward and left is active.