[Sidefx-houdini-list] Emitter velocity
andy at andynicholas.com
Thu Oct 25 09:26:44 EDT 2007
Thanks for your help guys. Got it sorted :-)
> Use a trail SOP to compute the velocity of the source/emitter geometry,
> and then set the source POP to "use inherited velocity" or "add to
> inherited velocity." The global variables $VX,$VY,$VZ, or the point()
> expression can be used to access velocity elsewhere. You can also
> calculate the magnitude (speed) of the velocity vector using
> length($VX,$VY,$VZ). CHOPs can be used to calculate change in
> acceleration, etc.
> A ndras Ikladi wrote:
>> Hi Andy,
>> The simplest I can think of is a trailSOP then using point() sample a
>> point's velocity attribute.
>> Alternatively feed the transform to CHOPs and derive the speed there..
>> but then you need to take both rotation and translation into account.
>> ps: say hi to the guys at Axis, if you happen to head that way :)
>> On 10/23/07, Andy Nicholas <andy at andynicholas.com> wrote:
>>> Can anyone tell me how I can get the velocity of an object into an
>>> expression? I need to vary the direction of emission of some particles
>>> based on their emitter's velocity.
>>> I'm sure there's a simple answer, but I haven't found it yet!
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
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> erik zimmermann
> effects artist
> digital domain
> 300 rose avenue
> venice, ca 90291
> 310.314.2800 x2369
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