Is there a way to deform instances by strands?

[Pancho]

I managed to create a set-up which enables me to deform copied topology. But as you might guess, this starts to become very slow with more than a few copied objects. I wonder what one would do with blades of grass or wheat which gets deformed by the wind (in close up). There would be 100k+ to make it look solid.

Any ideas?

[nixx]

I managed to create a set-up which enables me to deform copied topology. But as you might guess, this starts to become very slow with more than a few copied objects. I wonder what one would do with blades of grass or wheat which gets deformed by the wind (in close up). There would be 100k+ to make it look solid.

Any ideas?

If I understand correctly, you 're using actual mesh copies (topology). Unless you have a specific reason for this, you can switch to instances - then you can easily have thousands (probably millions) of them, and they can be deformed along their respective strands.

[Pancho]

Hi Nixx,

are you talking about SRT transformations? I actually need to transform point positions, bend the geometry along the strands. I just did a test with 512 cylinders, octagon base shape and 20 division in y direction. Took about 2-3 seconds each frame for the deformations. And that's nothing compared to what you really would need for grass or wheat.

With grass I could imagine that SRT transforms could work, at least in a certain distance. Hard to tell whether a band blade of grass is even more bend or not. But with wheat or other objects it would be a different thing. Then you actually need to transform point positions. And I wonder if that is possible with instances. With topology it's working, verrrrry slowly.

[mattmos]

You can use the StrandDeform attribute. Also check out the compounds posted by Sandy Sutherland in this thread, they should help you a fair bit:

https://groups.google.com/forum/#!topic ... xm2zo6CiI4

[Pancho]

Thanks Matt! That's what I was looking for!

[mattmos]

No Probs, and nice work on the dandylion so far - looking forward to seeing your fields when they're done!

[Pancho]

Any idea why the deformed instance flips on the y axis? And thanks for the compliment!

[mattmos]

Not sure why but they decided to create them that way! Found this info about it:

Note the the instance put the top Y of your instance at the particle
position and the bottom of your object at the strand tip, which means
you might need to invert your strands or scale your instance object by
-1 Y and freeze it's scaling to put it in the proper direction.

[Pancho]

A - ha!

That makes, ..... , sense. Mmmmhhh......

: )

Thanks!