how to rotate the cylinder

[lizhigang34]

I want the cylinder to rotate automatically..
How should I do? Please give me some code.
the cylinder is IAnimatedMeshSceneNode.

[frostysnowman]

in your irrlicht loop:

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cylinderNode->setRotation(cylinderNode->getRotation() + irr::core::vector3df(0, .1f, 0));

(if you want to rotate it on it's y axis)

[Ion Dune]

Please refer to the tutorials (numbers 3, 11, and 13 all do what you ask) and the docs before asking questions - it will save both your and our time .

[lizhigang34]

in your irrlicht loop:

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cylinderNode->setRotation(cylinderNode->getRotation() + irr::core::vector3df(0, .1f, 0));

(if you want to rotate it on it's y axis)

I want to rotate it on it's middle axis,and it's middle aixs will change,the middle axis is not parallel the X or Y axis,it's a rand vector,how should I do??

[rogerborg]

The code shown above will rotate the cylinder around its own Y axis, rather than the world Y axis. It should do what you want.

[lizhigang34]

In my program,the cylinder has a position,the position will change.But,no matter the cylinder how to change position,it will be cross vector (0,0,0).
Now,I want to the cylinder rotate around vector (postion - vector(0,0,0)).
Can you get my thinking?My English is poor.

[vitek]

I don't understand at all. The result of position - vector3df(0, 0, 0) is position. Do you want to rotate the cylinder around the vector that represents the direction from the origin of the coordinate system?

[rogerborg]

Can you get my thinking?

No, sorry. How about you post your code?

[lizhigang34]

I don't understand at all. The result of position - vector3df(0, 0, 0) is position. Do you want to rotate the cylinder around the vector that represents the direction from the origin of the coordinate system?

No,I just want rotate the cylinder around it's middle axis.this axis is vector(vector3df(position) - vector3df(0,0,0)),because the cylinder cross the point(0,0,0) all the time.the cylinder is IAnimatedMeshSceneNode which I load from a file.

[lizhigang34]

Did I express myself unclearly??

[vitek]

Yes. Repeating yourself doesn't help either. Describing what you mean in a slightly better way (perhaps with graphics or ascii art) would be more useful.

As I understand it, you have a cylinder. See below...

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     Y axis
     |
    _|_
   / | \
  |\___/|
  |  .  |
  |  .  |   Z axis
  |  .  |  /
  |  .  | /
  |  .  |/
  |  .  |
  |  .  |
  |  .  |_______ X axis
   \___/
     |
     |

You want to rotate the cylinder along the dotted line. In other words, you want to rotate the cylinder on the axis that runs the length of the cylinder, which, in this case is the Y axis. This is as simple as the code posted previously.

If you want the cylinder to turn in other directions, all while it is spinning, you would handle those other rotations using a parent scene node. At least that is the simplest way to do it.

Travis