intropop_tut

open Houdini ,


steps 1 -4 are the same as the sop tutorial

step 1:

hover your mouse over the parameters window.
hit "tab" and while the tab menu is open
type "geo"
just drop the node any where in the parameters window.

step 2:
now select the "geo1", and rename it to "pop"

step 3
next highlight the node that was just renamed to "pop" and hit "enter".
you are now inside the SOP level .

step 4
you see a "file node"...
now smite the node named "file1" with your mighty mouse by highlighting and deleting it.





Step 5

lay down a grid.

Tab, grid, enter.


In the grid's parameters

change size to 25 , 25

and row and columns to 2







Step 6
right click on the lower gray rectangle for the grid,

tab menu should pop up.
Type trans

select transform and drop it into your node window.


In the parameters
tab for transform
change

rotate Y to $F*4




$F*4 means that the object will rotate on the Y axis , * it by 4 speeds it up a little .







Step 7

right click on the lower grey rectangle for the Xform ,
tab menu should pop up.
Type Pop
select Popnet and drop it into your node window.


Make sure xform is connected to the left input.



Highlight the popnet and click enter to go inside of it.

It is empty:


lay down a “source pop”

tab, source , enter

you are now giving birth to a pop network .


Notice 2 things :

1 . the tab menu at this level is a little different then the one at the sop level.. these tools are popnet specific

2. the source node is an angry color red.


Step 8 setting up the popnet

Source pop


in the parameters window for the source pop,
select the source tab .

In Geometry source :

select first contact geometry

now your source is a happy gray color again.

And you can see a grid in the viewer.

At this point you can play the popnet

but nothing is happening.

To make something happen :
click the Attributes tab in the source pop parameters .

And select add inherited velocity

now if you play random little particals come flying out the corners of your grid.

While still in the attributes tab .


Set Y velocity to 2

set X Y Z variance each to 10









velocity is a directional force . Setting it to 2 in the Y will push the particals up.

variance is a random direction , that will scatter the particals , setting then uniformly to 10 with evenly splay the particals in varied directions.
.



next select the Birth Tab in the Source pop.

Set

impulse activation to 1
impulse birth rate to 42
constant activation to 0
constant birth rate to 0


life expectancy to 10
life variance to 5



now play and marvel at your handy work












Step 9 adding a force: wind

when your done marveling at your handy work,
stop playing and return to 0

next lay down a wind pop


right click on the bottom of the source node,
type wind ,
hit enter


set wind Y to 20,

this will force the particals up faster.


Step 10 adding color

right click on the bottom of the wind node, type color , hit enter

in the color parameter tab , select ramp

go nuts, select a few colors to place in the ramp.

At the bottom of the ramp tab You see some code.





Delete the code and replace it with $LIFE
all capitals.


$LIFE tells the colors to change over the life or duration of the partical.
It will cycle threw the ramp from begging to end until it dies . This can be used in things like Fire , that change colors depending on the heat of the flame .


Now play your creation and oooooh at your colors .

Step 11

return to the SOP level .

Laydown a tube

(tab, tube, enter)


now playing with the parameters and some basic basic scripts .

Set the Orientation of the tube to the Y axis


Center the tube at :

x 5
y $F
z $T









$F will move the tube by the frame # that it's on.
$T moves it by what time it's on. This is offsetting it from the particals by these increments ..

I did this for no other reason then to do it.....

Radius is 0 and .5 this will turn the tube into a cone



Step 12

lay down a copy Sop

(tab, copy, enter)
plug the tube into the left ,
plug the popnet into the right

in the parameter of the copy sop, select the Attribute tab , and check use template point attributes






now play . You should have a swirly vortex with pretty colors .

Mary-Margaret? Conley online at marymconley.com/hf