hi
i'm going through “lesson10: particles.”
i have a set up of a sphere shooting down particles and 50%of them belongs to “A_group.” and A_group particles are blown by popfan. then the instructor added “velocity” node to slow down x and z directions by adding $VX*0.9, $VY, $VZ*0.9 in the velocity field.
however, it seems like $Vs are no longer working(it game me red error) so i used @v.x, @v.y, v.z instead. but now all velocity in A_group becomes 0s.
what did i do wrong?
thanks,
hb
velocity attributes
11623 10 0
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- garin2
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- Enivob
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Instead of typing in the Velocity fields use code in the VEX window. Also remember to enable the popvelocity node, in your screen shot you have it turned off.
Adjust multiplier as needed.
Adjust multiplier as needed.
v = set(@v.x*0.1,@v.y,@v.z*0.1);
Edited by Enivob - June 10, 2016 09:11:23
Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
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- old_school
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Yeah POP Velocity DOP along with all the other POP * DOP's do not work with local variables at all. You can key frame these values but that's about it there. Don't use expressions in these parameters.
Use Enivob's wrangle expression above.
or…
or
and add a spare vector float 3 parameter to the POP Velocity DOP's interface to tweak with parameters. See the image for the sequence visually.
This is the exact reason we added wranglers to Houdini in the first place: to write/wrangle quick expressions in POP * DOPs.
Use Enivob's wrangle expression above.
or…
v = @v * {0.1, 1, 0.1};v = @v * chv("vel_scale");This is the exact reason we added wranglers to Houdini in the first place: to write/wrangle quick expressions in POP * DOPs.
There's at least one school like the old school!
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- garin2
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thanks for the various method. got that figured it out.
can i ask one more question on the next example? in the next example, he set any particles below -2 in Y axis he group them.
so i enabled vex and typed
ingroup = @t.y < -2;
but i got an error. what's the proper way to do this?
thanks again,
hb
can i ask one more question on the next example? in the next example, he set any particles below -2 in Y axis he group them.
so i enabled vex and typed
ingroup = @t.y < -2;
but i got an error. what's the proper way to do this?
thanks again,
hb
Edited by garin2 - June 10, 2016 19:58:57
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- old_school
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ingroup = @P.y < -2;
t works in those wranglers that has an explicit “t” named parameter that supports local wranglers. With these you can read and write without the “@”. Not in the POP Group DOP though.
@P returns the incoming point position.
If you forget the globals, just put down a POP VOP DOP, dive in and inspect the name (not label) of the outputs on the Global Variables VOP.
There's at least one school like the old school!
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- garin2
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as a beginner which variables are working in POP, DOP, or VOP is the most confusing to me. it would be amazing if there is a list or something that i can refer to.
could you explain what you meant by “put down a POP VOP DOP, dive in and inspect the name of the outputs on the Global Variables VOP”?
this seems like what i was looking for. i want some reference example where i can look into it. this will sure solve a lot of my questions and significantly reduce my postings. :-)
thanks jeff,
hb
jeff
If you forget the globals, just put down a POP VOP DOP, dive in and inspect the name (not label) of the outputs on the Global Variables VOP.
could you explain what you meant by “put down a POP VOP DOP, dive in and inspect the name of the outputs on the Global Variables VOP”?
this seems like what i was looking for. i want some reference example where i can look into it. this will sure solve a lot of my questions and significantly reduce my postings. :-)
thanks jeff,
hb
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- mestela
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- mestela
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- old_school
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- garin2
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- mestela
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A combo of words, gif, hip is hard to beat.
Licecap is easy to use, free, runs on OS X/Windows, and Linux via wine.
http://www.cockos.com/licecap/ [cockos.com]
Licecap is easy to use, free, runs on OS X/Windows, and Linux via wine.
http://www.cockos.com/licecap/ [cockos.com]
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