windblown trees

Started by Dune, June 05, 2017, 08:56:03 AM

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Dune

I had another go at bending a pop of trees one way (wind), but can't seem to get it right. Tried almost everything, also transform shader set at world position. Does anyone have the perfect solution?

masonspappy

 Are these static images or are they Animated?
I don't think I will be much help with animation, but I did some work with windblown three populations a couple of years ago and it was something of a pain. I had four basic Xfrog trees  and had to create 2-3 additional versions of each tree, each bending somewhat on the main trunk and bending more toward the very top of the tree. It also required two-sided leaves, with the underside a lighter green then the top sideand exposed  into the direction of the Blowing wind.   Then had to Sent the rotation parameter to confine rotation within a narrow range  that the wind was blowing in.

zaxxon

A possible alternative would be to use the wind generator in Speedtree to set the extent of the effect, then export a short mesh sequence to Lightwave and select the single mesh you like for export back to TG. ST exports both MDD and FBX MC Format, I think LW works with MDD at least. FBX MC allows a single frame to be exported from ST per the Docs.

Dune

Thanks guys, but that wouldn't solve my 'problem'. If you export a single bent tree, instances will still rotate and bend every direction. I want TG to bend a straight tree, and all its instances in the same direction. So, bend it not by its own axis, but globally. It would be a very welcome feature I suppose, as you can bend grasses by 'wind', etc.

luvsmuzik

Don't you have to have the object rotation range zero zero before you apply those nodes for them to rotate evenly? The trees are doing what you want, but they are at random rotation, no?

bobbystahr

something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Dune

Yes, of course you can decrease rotation to say 60º and have them all blown in sort of one direction, but you miss the 'variety' of 360º rotated tree(s). I want them to rotate full, and then apply global mesh displacing in one direction. I'm sure Matt can think of some fancy code, one day  ::)

luvsmuzik

You can make more populations by changing the origin rotation with individual trees also if you do not want cookie cutter looking tree farms. If you make a group object of say... three rotated (for variety) trees, set rotation zero-zero; then couldn't you then apply that rotation (wind-blown) to a population of the grouped object?

KyL

I think what you're doing goes against the principle of geometry instancing itself: if you were to have trees with random rotations plus wind bending them in the same direction, it would mean that they basically all have a different shape.
My understanding of instancing is that the geometry of the object has to stay the same (same number/position of vertices)

What you are doing looks correct to me, it simply means that Terragen is applying the deformation before instancing the object and not after, which is what you are looking for.

I'm curious to hear about Matt's call on this too!

Dune

Indeed.

@luvsmuzik: That's a way, yes, but you need three (or more) different trees with each a rotation of say 45º (for a bit more variation). I'd rather have it with one object, so it's more a testing of coding possibilities in TG. I just added a feature request in alpha.

paq

Hi Dune,

Well even if you manage to do the bending post instancing (so all instancing are bend in the same direction) , I'm afraid that just a bend will never look that great ... I mean, you need to manage branch stiffness and leaves orientation to get something convincing.
I do think too that it would be easier to export 10-20 seeds from a tree model with this wind feature  (speedtree / growfx can archive this very well).



Gameloft

Dune

You may well be very right, but I'd go for a subtle effect anyway, perhaps most important being grass and cereal fields being blown one way by gusts of wind. Those objects are easy to manage.

bobbystahr

Quote from: Dune on June 07, 2017, 10:07:22 AM
You may well be very right, but I'd go for a subtle effect anyway, perhaps most important being grass and cereal fields being blown one way by gusts of wind. Those objects are easy to manage.

The wind effect on cereal/grass fields I've noticed most in the prairies here is the rippling/wave motion that occurs in gusting winds...not in solid from 1 direction winds though.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Dune

Yes, but still you'd have to have a global way of bending them. I will keep thinking about this....

bobbystahr

Quote from: Dune on June 08, 2017, 02:06:30 AM
Yes, but still you'd have to have a global way of bending them. I will keep thinking about this....

Indeed, but once you did you could mask it with an animated PF to do the ripple effect..sure would look cool.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist