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Author Topic: Transforms follow a spline?  (Read 2353 times)

jonavark

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Transforms follow a spline?
« on: March 22, 2012, 03:56:03 PM »
I have to make a number of intricate crop circle animations. I am curious, can you suggest a way to get plants to lay down in particular directions? For example, following a spline and lay down by connection of a transform axis to the spline direction?  I have been doing this by hand for some of the shots and I have a very complex one to animate now.

For example, if I have to have laid down wheat fill a bunch of text..

Thanks!

iToo

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Re: Transforms follow a spline?
« Reply #1 on: March 22, 2012, 05:36:24 PM »

There is two ways to modify the orientation of the items along specific directions:

- In Custom Edit mode, using the Creation Tools as Along a Path->Follow Path, or using other items as reference.
- In Generate mode, using a Rotation Map. Although in this case would be a bit tricky to get the right map:

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

Recently, Jonny Allen made a presentation of this technique, used for one of his scenes, at AAUGA Boston. You can see the video here:

http://blog.konng.com/wp/2012/02/20/forest-pack-pro-presentation-at-aauga-boston/

Carlos Quintero
iToo Software

jonavark

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Re: Transforms follow a spline?
« Reply #2 on: March 22, 2012, 06:49:02 PM »
Thank you. I will look into both of those. I had considered maps but I can't wrap my head around proper creation of them..


jonavark

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Re: Transforms follow a spline?
« Reply #3 on: March 22, 2012, 09:12:55 PM »
I think the vertex paint mode will work for me but I am a little confused about how to set it up and get my forest object to use the vertex paint values..

The video links were excellent but it didn't show how the paint was set up..

thanks again.

iToo

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Re: Transforms follow a spline?
« Reply #4 on: March 22, 2012, 10:27:57 PM »

In this case Jonny uses the Viewport Canvas to paint interactively the rotation map. Each color (from black to gray) defines a degree or rotation (from Min% to Max% in the range parameters). For example, if you paint using a gray color (128/128/128) and the rotation range is 0º / 359º, the items will be aligned with a rotation of 180º.

You also must take in account that each component RGB, defines one of the directions XYZ. So, to rotate in Z, it is necessary to convert the grayscale map to a blue range. This can be easily done using a Color Correction textmap, as shown in the screenshots of the documentation.

Basically, the rotation map is a map of normal vectors. All techniques about normal maps are applicable here.

Carlos Quintero
iToo Software

jonavark

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Re: Transforms follow a spline?
« Reply #5 on: March 22, 2012, 11:23:35 PM »
yes... but he was using vertex paint instead of viewport canvas and I was a little confused as to how he set that up for interactively going the positioning. I have been trying to get that going here without any luck..

iToo

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Re: Transforms follow a spline?
« Reply #6 on: March 23, 2012, 12:04:59 AM »

You are right, i just saw the video again and he uses vertex color, not the viewport canvas. The tecnique is similar, please try this:

1) Create a surface with enough subdivisions (as a plane of 50x50)
2) Add a Vertex color map to the rotation map of Forest. Turn on Z, range 0-360º
3) Set the rotation map channel to 0
4) Assign the surface to Forest and turn on the "Auto" checkbox
5) Now you can use the vertex color paint tool to modify the alignment at real-time

One update on my previous post: if you want to modify only the Z value, it is not necessary to adjust the map to the blue range. Turning off the "Color Map" checkbox in the transform properties is enough.

Carlos Quintero
iToo Software

jonavark

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Re: Transforms follow a spline?
« Reply #7 on: March 23, 2012, 12:12:50 AM »
I must be doing something wrong.. thanks for your post! I have never used vertex color so I am stumbling there.  I will go through the steps until I get it right!

Thanks again, above and beyond the call of duty!


Q>

Do I have to assign a standard material to the plane with the same vertex map in it?
« Last Edit: March 23, 2012, 12:39:00 AM by jonavark »

jonavark

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Re: Transforms follow a spline?
« Reply #8 on: March 23, 2012, 02:01:17 AM »
OK.. I think I am getting it... but in Max2011 it seems I have to hit "Assign" in the vertex paint modifier in order to see the changes in my forest objects.. Can't quite get the real time part going..

OK.. I got it.. the auto button on the surface rollout.. (there's a couple of auto buttons! )

thanks for your help on this!
« Last Edit: March 23, 2012, 02:20:26 AM by jonavark »