Orientation of instances deformed by strands?

[Morten Bartholdy]

I have strands with turbulize on and instance shape so the instances are deformed by the strands - all good. I have hit a snag though - I can't seem to find a way to control the instances y-orientation. I have tried Milan Vaseks Randomize Local Y-Rotation node which works in the wiewport where I see non deformed instances, but at rendertime I get deformed instances all oriented as the master, so they disregard the y-rotation node.

 

This is what I am doing:

 

http://dl.dropbox.com/u/763668/ICE/Strands_Instances_hardware.jpg

 

http://dl.dropbox.com/u/763668/ICE/Strands_Instances_deform.jpg

 

I am guessing I need to apply an up-vector to the deformed instance, but can't really figure out how. Do any of you ICE-hads have a suggestion on how to deal with that?

 

 

Best Regards

Morten Bartholdy
VFX Supervisor/3D Lead
www.gimmickvfx.com

[Olivier Jeannel]

Isn't it because the BendStrandsTowardVector comes after the Orientation of the particle ?
Maybe try an orientation after the BendStrandsTowardVector.

[Morten Bartholdy]

Currently my only and kind of dumb workaround is to use prerotated instances in order to get some variation on y-axis rotation on instances deformed on strands. The only place I have seen this handled is in Tekanos tutorial on creating flowers that bend, as there is some rotational variation on those, but having gone through that tutorial I am unable to achieve the same thing.

I just want to be able to add variation to the y-axis rotation of my instances, while they are deformed by strands (grass and flowers stuff) but I keep hitting a wall here. This is not very well covered in the docs, and seemingly neither in the available tutorials, except maybe in some of the online commercial tutorials. I dont mind spending the money to learn, but I hate having to spend several hours trying to find out something like this, that ought to be extremely simple.

Could some kind soul hint at how to solve this?

- Morten

[Rob Chapman]

Hi Morten,

Tekano here!   I would have chipped in earlier if I was sure of what it was you are trying to achieve, now I get it.  If you are using similar technique to what I described in that tutorial then, as far as I'm aware, the strand instances are orientated by a simple 'randomize rotation by curve connected to the orientation of the pointcloud in which the strands are made - see pic attached, there is an example scene file attached at the very bottom of that tutorial as well with it all setup correctly.

hope that helps?

Cheers

Rob (Tekano)

[Morten Bartholdy]

Thank you so much, Rob and Oliver. Your setups are almost identical and do the job fine :) I compared my setup with yours and cleaned it of anything unnecessary, and now it works too. You have been very helpful - I wonder if there is a switch for deformation direction, because this way my instances are deformed upside down. Not a biggie but slightly messy.

Also I dont quite get why turbulize strands don't deform the strands in an unsimulated tree when animate is on!?

Docs: "

Animated

Toggles the activeness of the Animation Speed parameter. You can use these options to animate the strands with turbulence when using an unsimulated ICE tree (such as if the point cloud's ICETree node is in the Modeling region).

It works in a separate simulated tree.

 

Happy grass spreading camper now :)

 

- Morten

[Grahame Fuller]

That description is misleading. It’s actually controlling whether the turbulence field is animated.

gray

From: softimag...@listproc.autodesk.com [mailto:softimag...@listproc.autodesk.com] On Behalf Of Morten Bartholdy
Sent: Monday, March 19, 2012 12:12 PM
To: soft...@listproc.autodesk.com
Subject: Re: Orientation of instances deformed by strands?


Thank you so much, Rob and Oliver. Your setups are almost identical and do the job fine :) I compared my setup with yours and cleaned it of anything unnecessary, and now it works too. You have been very helpful - I wonder if there is a switch for deformation direction, because this way my instances are deformed upside down. Not a biggie but slightly messy.



Also I dont quite get why turbulize strands don't deform the strands in an unsimulated tree when animate is on!?



Docs: "

Animated


Toggles the activeness of the Animation Speed parameter.

You can use these options to animate the strands with turbulence when using an unsimulated ICE tree (such as if the point cloud's ICETree node is in the Modeling region).




It works in a separate simulated tree.



Happy grass spreading camper now :)



- Morten







Den 19. marts 2012 kl. 14:41 skrev Rob Chapman <tekan...@gmail.com>:
Hi Morten,

Tekano here! I would have chipped in earlier if I was sure of what it was you are trying to achieve, now I get it. If you are using similar technique to what I described in that tutorial then, as far as I'm aware, the strand instances are orientated by a simple 'randomize rotation by curve connected to the orientation of the pointcloud in which the strands are made - see pic attached, there is an example scene file attached at the very bottom of that tutorial as well with it all setup correctly.

hope that helps?

Cheers

Rob (Tekano)