hairfx workflow

[Adam H. Stewart]

I have done a couple of searches on this topic and come across various replies non of which really answer my question - forgive me if it has been asked before. The effect I am trying to achieve is a large field of waving try grass.

Firstly does the hairfx shader work with Vray? - I have tried it a few times and gotten some really strange results.
What are are advantages of converting the hair to a mesh ? - does this mean that I can use some decent vray materials ? - does it kill animation I might have set up?
Does hairfx work with the vray lights?
Is there any point in me even attempting to include the hairfx in GI calculation?
Should I be using Vray fur ?

Thanks in advance for your patience and help.

[joconnell]

Heya Adam. We used hair FX in geometry mode on the milk ads and it worked fine. The benefits are that you do indeed get full use of vray materials and you dont have to worry about vray camera motion blur and hair fx post motion blur matching up properly since it's all done in one shot. likewise it means you can use your vray lighting setup to light the hair too - again no need for seperate lights for your hair. In my experience it looks very different working in geometry mode. It won't be as soft and again since you're dealing with tonnes of small geometry, it may cause a hit on your render times. You can control this by limiting the amount of knots that hair fx puts into each hair (the same as interpolation steps in a renderable spline).

Vray fur is more of a proof of concept than anything at the moment - It mightnt do all that you need. Can you be more specific about what you want in the end?

[Adam H. Stewart]

Grass - looks and progress

A really bad image from "What's eating Gilbert Grape" that is the what this is for, the grass I am trying to emulate is like the grass on the right side of this shot - but in the summer (less tangled):
http://h1.ripway.com/Adam_Stewart/Grass_01.jpg

Here is an image of progress ? to far. The sky is a bad dreamscape comp, the background trees are jpegs on plates the nearer trees are Oynx. There is no GI because the grass coulnd't handle it:
http://h1.ripway.com/Adam_Stewart/Hairfx_Render.jpg

Here is what the Art Director is looking for :
http://h1.ripway.com/Adam_Stewart/wegg_look2c.jpg

Thanks a million for your help.

[DaForce]

Not sure if this will help much but have a look at this old ass thread of mine. Has some grass.. somewhat similar to what your trying to do (I think)

http://www.chaosgroup.com/forum/phpB...ight=dry+grass

Anyway, either way what ever you choose has to be done via geometry.

[Adam H. Stewart]

Thanks

Thanks a million that is very similar to look I am after alright, maybe with some thiner stalks thrown in. That scene looked great. Converting to Geom seems the way to go.

I will have to limit my grass area as at the moment I cannot even imagine how many ploygons I would get. I am playing around with vray proxies at the moment and am not having much joy on the viewport front. Basically whenever I copy a proxy it dissapears - I am using 3ds 7.5 with Nvidia FX Quadro 3000. I have tried using several different drivers Direct 3D, Maxtreme 8 ect. but the viewport representation seems way off, or just not working - any idea's ?

Thanks for the Grass man

[DaForce]

hehe glad it helped you out

With Proxies .. once you have them in the scene.. you cant copy them.. you have to instance them. Otherwise they disappear

Not 100% sure what you mean by the viewport representation? post a pic?

[Adam H. Stewart]

Thanks again

Again I am giving you many props. That was exactly my problem. I was copying them and they went away. But Instances where fine. I think my concept of Proxies was off base. I did some tests before leaving work and they rock, super fast aswell.

[DaForce]

heheheh always happy to help.

Post some results
If you need any more help .. well you know.. post here

[Adam H. Stewart]

Early tests with HairFx as Geom

Here is an early test. Now I am using a Standard max material as I couldn't seem to get the right specular from the Vray material. I am a bit of a clutz when it come to Vray materials. Max material make alot more sense to me - I miss a specular slider. Here is the test - I need to probably decrease the stalk thickness and increase the density - aswell as try some bending.

http://h1.ripway.com/Adam_Stewart/Ha...ndered_Gem.jpg

The light is a single Direct with Vray shadows (area shadows off). I used a bit of environment override aswell .4 or something. Irradiance map settings are quite high as is Light cache.

Let me know what you think .

Thanks as always.

[joconnell]

Actually for this type of mossy grass you could try using displacement instead - it kind of looks like grass from a train set or the such - here's a quite run through - http://vray.info/topics/t0049.asp

[Adam H. Stewart]

Looks great

That Hedge looks great - I'll have to give displacement a shot, maybe with a few strands of the hair to break it up. That looks really great - thanks.

[Da_elf]

i used to use druid grass. was a cool plugin since it gave you nice control over your grass and also allowed for wind animation on the grass automatically

[Adam H. Stewart]

Hairfx Grass Nightmare

http://h1.ripway.com/Adam_Stewart/Wht99_C1_0068.jpg

http://h1.ripway.com/Adam_Stewart/Wht98_C2_0067.jpg

I have posted a couple of images of how my grassland scene is looking. I am having all sort of problems with Hairfx flickering when I try to animate (it looks like a shadow map issue) The wavewind force seems pretty useless and there is no documentation on the settings, you can use standard forces but cannot animate their location or rotation - Arrgghhh !!
I had to turn of convert to Geometry as my machines couldn't handle the load. I also had to turn off GI for the same reason. This grass thing seems an ungoing nightmare in my World ( and Vray from the posts I see here) I am going to try to create my own using a scatter object - animation on that will be fun.

Wish me luck

Thanks as always for you help and advice.

[mike.edel]

depending on the version of max you are on, you could try grass-o-matic (free but discontinued plugin by www.sisyphus.com)
example tuts:
http://www.3dtotal.com/team/Tutorial...m_glade_01.asp
http://www.3dm3.com/tutorials/grass/

plugin:
http://www.cadalyst.net/extras/plugins/Objectmax5.html
grass-o-matic is/was part of the druid plant plugin by sisyphus
still availlable for max5, grass-o-matic is fully functional without any need of licensing
http://www.cadalyst.net/extras/plugi...Max5/druid.zip

has wind controls, too as far as i remember

edit:
interface screenshot:
http://forum.3dmaxforum.de/attachmen...5&d=1037880427

[DaForce]

hmmm putting grass over that large area... you sure do have your work cut out for you.

Does it have to be animated? perhaps you could use planes w/ alpha maps and then use scatter or pflow to spread them around.