fbitonti
08-16-2011, 04:13 AM
I am new to Houdini. I have been reading the documentation for the l-system functionality at the following link.
http://www.sidefx.com/docs/houdini10.0/nodes/sop/lsystem
The text I am reading has been copied here as follows.
"Limit L-system growth inside a shape
The L-system node’s meta-test input lets you generate rules that will cause the system to stop when it reaches the edges of a defined shape, like a topiary hedge.
Create a metaball or merged metaballs that define the volume in which the L-system can grow.
Connect the metaball node’s output to the Meta-test input of the L-system node.
Use a conditional statement (:) with an “in” test. For example:
Example
Premise
FA
Rule 1
A: in(x,y,z) = F [+FA] -FA : 80
Rule 2
A: ! in(x,y,z) = A%
This L-system checks to see if the next iteration of growth will be within the Meta-test bounds, and if not it prunes the current branch.
Rule 1 executes 80% of the time when the branch is within the meta-test boundary.
Rule 2 executes when the branch is not within the meta-test boundary (the ! negates the in(x,y,z) condition). The % command ends the branch."
Can someone explain to me how to make this work. I have been following the instructions and I can't get it. I think I am not connecting the L-system and the metaball correctly.
"Connect the metaball node’s output to the Meta-test input of the L-system node."
What is the Meta-test input? How do I find it?
Thank you in advance for your help. I greatly appreciate any advice you can give.
http://www.sidefx.com/docs/houdini10.0/nodes/sop/lsystem
The text I am reading has been copied here as follows.
"Limit L-system growth inside a shape
The L-system node’s meta-test input lets you generate rules that will cause the system to stop when it reaches the edges of a defined shape, like a topiary hedge.
Create a metaball or merged metaballs that define the volume in which the L-system can grow.
Connect the metaball node’s output to the Meta-test input of the L-system node.
Use a conditional statement (:) with an “in” test. For example:
Example
Premise
FA
Rule 1
A: in(x,y,z) = F [+FA] -FA : 80
Rule 2
A: ! in(x,y,z) = A%
This L-system checks to see if the next iteration of growth will be within the Meta-test bounds, and if not it prunes the current branch.
Rule 1 executes 80% of the time when the branch is within the meta-test boundary.
Rule 2 executes when the branch is not within the meta-test boundary (the ! negates the in(x,y,z) condition). The % command ends the branch."
Can someone explain to me how to make this work. I have been following the instructions and I can't get it. I think I am not connecting the L-system and the metaball correctly.
"Connect the metaball node’s output to the Meta-test input of the L-system node."
What is the Meta-test input? How do I find it?
Thank you in advance for your help. I greatly appreciate any advice you can give.