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challenge: FoRest gump...

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hi guys,

that's very cool.

i'm actually xsi user and new to houdini more or less, but interested to learn it a bit beside xsi.

and since i'm interested in this effect i was wondering if anyone could do a little tutorial on how this can be done... only if it doesn't take too much of your time.

thanks in advance

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hi guys,

that's very cool.

i'm actually xsi user and new to houdini more or less, but interested to learn it a bit beside xsi.

and since i'm interested in this effect i was wondering if anyone could do a little tutorial on how this can be done... only if it doesn't take too much of your time.

thanks in advance

15892[/snapback]

Why don't you check out the sollution files, attached by the contestants?

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hi guys!

i've been playing with this exciting challenge for an hour and finally

i came up with the copystamping of a custom attribute based on a distance() expression

to get a different scaling of my trees based on the mountain SOP geometry.

But it doesn't work out correctly, my trees do some unexpected scaling which confuses me a LOT!

would be nice if someone of you pros could point out where i got the setup wrong!!!!

Hipfile is attached,

thanks in advance,

regards,

Manuel

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I rebuilt the scene and could solve at least the scaling issue myself!

Then, i wanted to clamp all trees below 0 and created a group "groupabove0".

But everytime i try to copy my trees only to that template group, my scaling gets messed up.

why is that?

please have a peek at my latest scene,

all the best,

Manuel

my_forest_2.hipnc

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The problems comes from the fact that you are filtering the points and that is changing the point numbers. When you only copy to those specific grouped points, the point numbers no longer match up to the point numbers on the input, which is why your things start going weird.

There's a couple ways you could fix it. One is to introduce a local variable before the copy and use that, or instead of using the Template Group, use a delete to delete the non-grouped geometry before hand, then just do it like you were before. This ensures all the point numbers will match up.

Attached is the file that's been modified in both ways. I also added a VOP Sop to show another way of handling all the distance and group operations.

my_forest_3.hipnc

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I also added a VOP Sop to show another way of handling all the distance and group operations.

hey Graham,

once again thank you very much for helping me understanding Houdini a little better!

I love your VOP solution, learned a lot from your hipfile,

i have only one question:

in the twoway VOP every point that doesn't satisfy the condition gehts the integer -1.

Why -1? because the output is fed into the addpointtogroup VOP and there are no points such as -1 ?

all the best,

Manu

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Yeah that's basically it. It could be any number really, as long as it's not in the range of actual point numbers. Just a dummy value so we don't add points we don't want.

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Hi !

I've been reading this forum for a few months, but this one will be my first post here.

So hi everybody, and sorry for my english..!

I must say that the community here is impressive.

Everybody seems happy to learn or extremely happy to help.

So thanks a lot for that.

So, i'm gonna revive (once more) this challenge !

I've tried, and i think resolved, this exercise.

I mean, it's working...

The height of the trees is sticking to the offset surface, there is no trees were the offset surface go down, but...

...but as Asnowcappedromance said 3 years ago, there must be a better way to do this !

And i would really love to learn from my mistakes.

So if someone could see my scene and say " tsk tsk, that's all wrong, look: " I will be really gratefull.

Too, i'm quite sure that houdini 12 is a looot more easy to work with than the version of 2002 !

Sadly i'm unable to open the olds scenes, due i'm sure to this 10 years gap eheh !

Jason, for exemple, said that he did it with just a simple expression, when i've used a "simple ray node" and stamps etc.

So, is there anyone (Jason ? :P) who could point me to the expression to use ? To resolve it in the "old fashion way" ?

Again, thanks just for having these challenges existing. It's a big place to learn.

François.

Here the image, and the scene.

post-7471-0-43961900-1348953914_thumb.jp

forest_001.hipnc

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extremely minor change, but removed the need for the stamping and scaling but stiroing an attribute and mapping it to the uniform scale,

makes it a little bit faster, and a but cleaner I suppose, but aside from that you pretty much did it as I would have.

forest_001_freek.hipnc

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