Need help creating, animating and rendering very long grass

[Morne]

Hi all

I've been going through various tutorials and searched varioud threads but just can't get what I'm looking for. 1st I tried doing this with Max hair and fur, but VRay has issues with hair and fur. Then I tried grass-o-matic which brings the computer to its knees when you have a 100m plane with 200 000 grass blades. Then I tried reactor rope which failed (well I get 1 grass balde to work but more than one is a mission). I also checked out the tutorial on 3dTotal but that is not what I want as it looks like underwater grass and I need something more random and dynamic. So the best solution I saw was done with Particle Flow however I can't figure out how they did it. I create my grass blade, then bend it. Well then how do I get it to stay on my plane and be animted bu wind? Also I'm rendering with brute force in both primary and secondary GI. The grass needs to blow like crazy from sphere wind that is very strong.

Help!

[Morne]

ok I have 15000 bent grass blades locked on my plane and they not going anywhere. I have a wind force in and they are effected by the wind. But they not moving. Was I suppose to animate my instaced shape before distrubiting it on the plane? But then of so, how can the wind effect anything if it is pre-animated?

[Morne]

OK for now I'm not rendering yet so not much about VRay here. Can a moderator please move this forum to "off topic" for now please!

[Morne]

After 2 weeks I'm going nuts trying to get this to work!

I really need some help here urgently! Grass-o-matic is not the correct tool for this job as it makes the grass looks like waves and it kills the pc. I'm using a ground plane 100m X 100m with 1m tall grass. Over that large surface I need minimum 250 000 blades of grass. Grass-o-matic is not made for this it seems. The 3d total tutorial also is no good as the end animation looks like underwater wave grass. Max Hair and fur seems to be a good option, however I can't get the sphereical wind to effect the grass nicely and VRAY doesnt like MAX hair and fur anyways. I modified the 3d total tut by adding flex instead of the wave, but that doesnt keep the shape of my grass, and it kills the pc during render time. So its either max hair and fur or somehow do it with particle flow which is the option I'm hoping for. Max particle flow seems promising but after distributing my object over the ground, I can't figure out how to affect it with wind.

I'm running Vista 64bit, MAX 2009, VRay 1.5SP2, Intel Q9550 2.8Mhz Quad Core CPU and 8GB Ram

Please help!

Regards,
DVP3D

[sv]

why not:

just stick with grass-o-matic, but make it in smaller clumps - 10m x 10m not 100m - then make an animated proxy of it and instance or copy around..?
worked really well for us recently...

[Morne]

the problems is that I need very crazy wind with grass flapping all over the place. Grass-o-matic makes it looks to much like underwater. My grass will be affected by downdraft of helicopter hovering low.

[sv]

and you want 1m tall grass? Does grass even grow this tall!?!
And you have a field of 100m x100m? hmmm
nightmare....

maybe you could approach it differently, like use VrayFur and use an animated map or something to control the initial direction and / or bend -
I think in any case, it would be better to split it up into layers or sections of something like 10mx10m. Even with 8gig of Ram 100m x100m is going to be a real killer....

Let us know how you get on and what you end up with!

[Morne]

Hi all

Somebody posted a file in my thread over at "The Area" of a field 20m x 20m and about 1m grass with Max Hair and Fur with spherical wind. After doing some modifications and adding another wind force and changing from mental ray to vray of course, this so far seems very promising and I've been getting very good results.

P.S.
I mixed up turbulance and frequency in my own tests, but after swopping the values around in the posted file, Houston we have lift off


Now if only I can get rid of the flickering. I'm not sure if Vray settings is the culprit, as hair is a post effect.