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Author Topic: Noob needs help with splines vs surfaces vs areas  (Read 2362 times)

QQ2643

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Noob needs help with splines vs surfaces vs areas
« on: June 04, 2012, 01:51:04 AM »
Hello everyone :)

I'm a bit confused regarding the surfaces and areas and splines.

If I import geometry from sketchup to 3dsmax and select an area for the vegetation then I need to use the 'surface' set to UV or else only the edge/border of the shape is is used for the distributions :s? 
I'm not sure what to so the swap it so the entire form is used without entering the 'surface' mode where some of the area options are disabled.

I have looked at the tutorials but i'm still confused.

I might explain myself badly, but to simplify it - If i'm in a situation where the border is used and the spline is closed then what should I do to make forest fill the form instead of only the edge?

Thanks! :)


iToo

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #1 on: June 04, 2012, 08:47:33 AM »

Forest can use splines or surfaces to define the scattering area. If you assign a surface, but not a spline then the items are distributed along the full surface.

So, the suggested workflow for a new object should be this:

1) Assign the spline as "Include" area -> the items are scattered inside the spline
2) Assign a surface -> the items are Z aligned with the surface

On the other side, the surfaces can work in two modes: XY or UV. The default mode is XY, and it is suggested for terrains. The UV mode is not compatible with areas, so probably this is the reason these option are disabled in your scene. You can see more information about the surface modes here:

http://www.itoosoft.com/forestpack/reference/refsurface.php

Anyway, in this case i think the problem is that the spline is not closed, probably it has some open vertex. For open splines, Forest creates the distribution surrounding the shape (exactly the behaviour you get).

Carlos Quintero
iToo Software

QQ2643

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #2 on: June 04, 2012, 01:05:47 PM »
thank you for the reply,

So do you recommend to mainly use splines for the distribution instead of selecting meshes from the current scene?

Thanks!

iToo

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #3 on: June 04, 2012, 01:17:38 PM »

Yes, because the splines include advanced features as falloff curves, boundary mode, etc.  Also it's easier to adjust the scattering area if you want.

Carlos Quintero
iToo Software

QQ2643

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #4 on: June 04, 2012, 03:04:52 PM »
great thanks,

Sorry i'm such a noob, but in 3dsmax, what's the best way to create an custom curve like a bezier spline that will work to define a custom distribution area, will a normal nurbs curve work or does it have to be a special type?


iToo

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #5 on: June 04, 2012, 04:07:12 PM »

A simple spline works a bezier curve, there are not special types for that.




Carlos Quintero
iToo Software

QQ2643

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #6 on: June 04, 2012, 06:50:59 PM »
Ok the lines (splines) make sense now and I have created a few. My terrain is sloping, does this mean i MUST use the surface area instead of the splines?
I have read the tutorials but it's confusing to me, usually me landscaping isn't just a flat surface, but i would like to use splines to define the distribution :S  ???

QQ2643

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #7 on: June 04, 2012, 06:55:20 PM »
the current situation is that i have a mesh with landscape contours, i would like to to populate a few areas of this mesh with the plants but it needs to be in precise locations. So can splines be used for this so the plants still follow the contours?

iToo

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Re: Noob needs help with splines vs surfaces vs areas
« Reply #8 on: June 04, 2012, 07:19:46 PM »
Yes, in that case the splines define the contourn, and the surface the elevation.

One more thing: when you assign a surface, the plugin adds automatically an entry in the Area list: "Surfaces Area". Be sure to turn it off when using together splines areas, if not Forest uses both objects to scatter (the spline and the surface), creating overlapped items.

I suggest you read the Forest reference for Areas, not only the tutorials. Some tutorials were created with previous versions of the plugin, and some features may be different. Instead, the reference is upated to the latest version:

http://www.itoosoft.com/forestpack/reference/refarea.php

Carlos Quintero
iToo Software