Anyone can tell me how to rotate particle instances?

I tried rotation pop but it doesn't give me control over the angle and axis separately.

Any tips?

mzigaib
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I tried rotation pop but it doesn't give me control over the angle and axis separately
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how do you imagine separate control over angle and axis?
i think they are separated enough in rotation pop
you can allways use vop pop for your custom rotations

Thanks you for the answer.

I forgot to mention that I already have a velocity orientating my particles, what I wanted to to add is some rotations to it, for example in the Z axis where I can thumble my particles with random values or a ramp based on it´s life.

I could do it with scale using VOPs but I didn´t figure out how to do it with rotations. I really didn´t understand how to control particle with the rotation POP when you have 1 angle controling 3 axis.

Can anyone help with this?

Sorry for the bad english

After the particles are aligned to the N (or velocity) you can use the ‘rot’ attribute to do an additional rotation.

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=6679 [sidefx.com]

The Rotation POP creates the attribute for you. Or you can do it manually.

Thanks for the reply.

I am aware of the rot attribute and rotation POP, the problem is I could´t figure it out a way to use it to rotate each axis with different values, for example:

X = 25
Y = 45
Z = 90

The parameters only allow me to set one angle for the 3 axis not one angle for each axis, I know that must be a way to do it right.

I also tried VOP but also I couldn't make it work right, it doesn't follow my angles right.

The only example file in houdini that´s available has an error and does not work right.

I also looked at the link that Wolfwood gave me but I didn't find my answer there either.

I just need a little help to understand how it actually works.

The ‘rot’ attribute is a quaternion. If you want to specify 3 Euler rotations like,
X = 25
Y = 45
Z = 90

then you should try using the Euler to Quaternion VOP.

WOW!!!!!

That´s it, that´s the key I was missing!

Man! Thank you very much Wolfwood! this was taking my sleep away.

That helped a lot!!!

I would like to ask help for on more issue if you or anybody else might.ops:

I would like to make my particles to auto bank as they turn, I tried to work with the up vector node but i didn´t have much success.

Any tips?

Anyway thanks very much again for the help everybody. :wink: