[Sidefx-houdini-list] rotating noise

Rangi Sutton rangi at kanuka.com.au
Sun Nov 25 21:14:11 EST 2007


Yeah.. you can do the rotation in maths in the sops but it's harder and 
more limiting than just rotating the source object around... then 
rotating it back afterwards.

Once you've set up your xform sops on either side of your noise sop you 
can also scale/shear/translate the noise easily!

Tip..
* make your initial transform sop
* RMB-Reference copy it
* tick the Invert Transformation at the bottom of the referenced copied sop.

This is faster an more flexible than putting -ch() expressions in.. and 
you don't need to worry about reversing the scale/rotate/translate or 
rotate x/y/z orders if you start doing more elaborate transformations. 
It gets it right for you.

Cheers,
r.



Alvin Yap wrote:
> Can you not rotate the geo, apply the noise, then do a relative 
> reference to the sop that did the rotation to get the inverse rotation 
> hence getting the geometry back to the original position with the noise 
> applied? I use that quite abit to scale groups of objects (shift geo to 
> origin, scale, shift geo back to original location).
>
> HTHs!
>
> Alvin
>
> Adrian Lee wrote:
>   
>> Thats the effect I want but is there anyway to do it with out rotating the
>> geometry?
>>
>> On 25/11/2007, Louis Dunlevy <ld at dneg.com> wrote:
>>   
>>     
>>> If you're displacing then try rotating the normal instead. So if your
>>> current expression is something like:
>>> $TY + noise(blah)
>>>
>>> try:
>>> $TX+$NX2*noise(blah)   $TY+$NY2*noise(blah)   $TZ+$NZ2*noise(blah)
>>>
>>> you can rotate your geometry and stick it into the second input of the
>>> point sop which picks it up via $NX2 etc..
>>> or do it in vops.. ;-)
>>>
>>>
>>> Adrian Lee wrote:
>>>     
>>>       
>>>> Hello boys and girls,
>>>>
>>>> I have a noise expression in the $TX slot in a point node that nicley
>>>> displaces some geometry in the YZ plane. How can I then rotate the noise
>>>>       
>>>>         
>>> in
>>>     
>>>       
>>>> X so the same noise is now applied at a slight angle? Thanks
>>>>         



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