hello all,

I am new in using Houdini and find that it is very powerful in procedural animation.

Recently, I am playing with L-system and want to create a tree(with leaves and branches)

I do this as follow(in SOP):

1. create a curve
2.transform it
(1 & 2 are to form the leaves)
3.add a shader of the leaves(green in this case)
4.link it to a lsystem-1 (which is the branches)
5.link to another lsystem-2 (which is the centrum)
6.add another shader (brown, for the centrum)


but, the result is that, the brown color donesn't show up, it remains its silver color (i think it is the default color)

I have no idea after playing different combination of box inside SOP.

if you have any ideas, can you give me some tips or hints so that I can fix the problem out.

Thank you very much.


Best Regards,
Benny Wai.

Have a look at the L-system helpcards and look up methods for creating groups in L-systems. You can use these to create groups for shading in a single Shader SOP. I've just been creating L-system trees using this method.

thank you for your reply…but can you show me the helpcards?

I search for the help in Houdini but it does not mention how to group lsystem.

i am still finding solution of it.

Thx very much ~

Click on the question mark on an L-system sop, then go to “creating groups” within l-systems, this is what you get:

Creating Groups within L-systems

There is a group operator ‘g’ which lumps all geometry currently being built into group g. For example:

g

lumps geometry from F into a group called lsys0. You can set the lsys prefix from the Funcs page.
Optional Group Parameters

g takes an optional parameter as well. For example:

g(1)

lumps geometry from f into a group called lsys1. If no parameter is given, the default index is bumped up appropriately.

The current group container is pushed/popped with the turtle state so you can do things like:

gF F

the first and last F's are put into group 0, and the middle FF's are put into group 1.
Example

Note the example:

gF F

The geometry from all four F's are put into group 0, (pushing the turtle adopts the parent's group).

To exclude the middle FF from the parent's group type:

gF F

thank you very much



I can fix the problem now ~