Vray + Displacement - Creating realistic GRASS???

[SSPEIPER]

Hi all,

I am after a good tutorial on making realistic grass in Vray for Rhino with displacement etc...

All the things ive seen so far either have no sound - or are too blurry to see what settings are used etc...

I have tried by incresing the multiplier and it only succeeds in creating very thick looking jagged edges (not like blades of grass at all).

I saw that on the ASGvis site that one of the moderators had played around with a FUR script - but until this becomes mainstream what can I do to achieve a realistic look?

A typical Vismat file I downloaded was like this:

1. I downloaded the - HiRes-Grass.vismat

2. Then I downloaded the texture zip file which includes the following:

- HiRes-Grass.jpg <-- I now this goes on the Diffuse area
- HiRes-Grass_DISP <-- I know this goes in the Displacesment area
- HiRes-Grass_SPEC <-- Where does this go?????

And along with the Vismat file do I install the textures first or after...

I am just starting with Vray so if you can help....thanks...

[SSPEIPER]

Re: Vray + Displacement - Creating realistic GRASS???

SO there is absolutely no-one with any help regarding creating grass in displacement...???

I insert the setting in the multiplier that the grass pic showed and yet it still comes out different...

What we need are complete setting to go along with a display PIC of each material...

Otherwise some of us are running around like headless chickens trying to get the damn thing looking like the example picture...

Do I have to convert to a mesh before displacement???

The grass does not come out thin like I want it to - instead it is all thick and jagged (more like spikes) Increasing the multiplier only makes them bigger - not thinner.

Can anyone shed some light and or post some decent settings...

[Micha_cg]

Re: Vray + Displacement - Creating realistic GRASS???

I have no experience with displacement, but so far I know, detailed displacement like to get render meshes (or meshes only) with not to less polygons. Maybe you use the mesh option "simple plane" and so, the displacement calculation dosn't get enough inital polygons.

[SSPEIPER]

Re: Vray + Displacement - Creating realistic GRASS???

Hmm! yeah I may have to post a pic or something...

Im still finding my feet with it so hopefully I will stumble across a solution myself...

Ill play around with turning the flat plane into a mesh and see what happens.

If Vray Fur (for Rhino) comes out that will be my problem solved....sort of

[Micha_cg]

Re: Vray + Displacement - Creating realistic GRASS???

Ill play around with turning the flat plane into a mesh and see what happens.

You can use the general mesh options of Rhino or the object properties custom mesh options (with preview). So you don't need to convert your NURBS to mesh, only the mesh settings must be adjusted.

[Micha_cg]

Re: Vray + Displacement - Creating realistic GRASS???

I found the files of my last grass test, maybe you like to play with it or someone find a way to speed up the rendering. The current render time of 38min (Q6600@3GHz) for the little image and only for some grass is to long for my need.

http://www.simulacrum.de/download/GrassDisptest.rar

[caje]

Re: Vray + Displacement - Creating realistic GRASS???

I know this has been talked over and over again...but in your opinion what is the best and fastest way of creting grass in V4R?
For this image Micha, you used the displacment material, correct?
The image looks realy great, and grass also!
But I think you also had a method with using big images and someking of special mapping thing on large ground planes...?!
Can you compare the 2 methods and the results. It would be grate if we have a side by side comparison of various methods when crating garss.

[thomthom]

Re: Vray + Displacement - Creating realistic GRASS???

I'm in favour of adding the grass in post for realism. To render realistic grass you really need Fur. Displaced grass will always look like displaced geometry...

[caje]

Re: Vray + Displacement - Creating realistic GRASS???

Not a big post fan here
Hey Micha whats your favorite way?

[dalomar_cg]

Re: Vray + Displacement - Creating realistic GRASS???

I don't want to speak for Micha, but I would guess that it would be the method that he posted some time ago.

http://forum.asgvis.com/index.php?topic=2320.0

[caje]

Re: Vray + Displacement - Creating realistic GRASS???

Yeap thats the one.
What was the time rendering for this techniqe?

[dalomar_cg]

Re: Vray + Displacement - Creating realistic GRASS???

Its just a texture so I imagine no additional time is needed

[Micha_cg]

Re: Vray + Displacement - Creating realistic GRASS???

Displacement is to slow for me, so that I never used it. If I render grass, than most I use a large texture with some bump. It's not the best realistic look, but speed counts. Last I added some arch vis images at my gallery, there is some simple grass visible.

The env mapping method is fast like every other texture, but quite limited for a view like seeing from a human. But often my clients like to get a bird view too, so I stick at simple textures.

[caje]

Re: Vray + Displacement - Creating realistic GRASS???

Why do you say the env mapping method is limited?!
I thought it was great*!?

[thomthom]

Re: Vray + Displacement - Creating realistic GRASS???

Because the environment map you use have to match the same eye ehight as the one you render from.
If you do a birds eye view you need an birds eye view environment map. That they are very hard to get hold of.