2008-03-03

V-Ray Grass

If you are using v-ray and don't use the VRayDisplacmentMod, then you should switch to mental ray! I use both, but v-ray is very powerful at performing geometric displacement, and is superb at creating organic objects; even grass looks good with displacement. Mental ray is good at displacing small polygons of geometry, where V-ray is good at displacing detail over large polygons. For this reason v-ray 1.50 sp1 is much more successful at creating grass for very large sites; a big plus!


A torus-knot with VRayDisplacmentMod modifier (light cache & irradiance map with 2 vray area lights)


The shader is simply just a VRayMat, with a grass map in the diffuse slot. Then I applied the VRayDisplacementMod modifier to the object. I instanced the image map from the shader into the displacement modifier.

VRayDisplacementMod settings:
• For something like grass it’s very important to use 2D mapping rather 3D mapping.
• I instanced the image map from the shader into the Texmap.
• I changed the amount to 4” to have taller grass blades.
• I increased the resolution to 2048 for better quality.




Voila, beautiful grass!


(notice the render times)

12 comments:

  1. Great stuff! I love the animations you post up to help communicate the content. I started up a 3ds max / mental ray site a few months ago. Hopefully I'll get some more tutorials up there soon. I found your site from the vizdepot forums . I'd be happy to link your site. I'm at SilkyPixel.com

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  2. I could watch this animation forever.

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  3. I got nowehre near your result :( It looks more like a lizard scale, not a grass :(

    http://i264.photobucket.com/albums/ii193/merraton/cos.jpg

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  4. metatron: try using uvw mapping modifier using the box setting. This should even out your map.

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  5. I'll try that tommorow. One thign crossed my mind - could it be connected to the scale of knot? Mine wasn't big, maybe that's the problem? Dimensions wasn't specified so I made a rather small knot.

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  6. I can not make the same as you did.
    Could you let us download the MAX file?

    Thanks.

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  7. @ramy:
    i was having the same problem as metatron, and your suggestion really helped! see the difference from before and after:

    before:
    http://img520.imageshack.us/img520/9096/beforexn5.jpg

    after:
    http://img520.imageshack.us/img520/5480/afternk7.jpg

    thank you very much!
    and also, i love this blog! is awesome! keep it up! ;)

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  8. thx for your posts .. but it would be even better if you stated step by step how you achieved this result .. thanks again for your useful posts .. i really like your blog :)

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  9. which is more realistic, Vray or Mental Ray?.... what is the difference between them?... thanks

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  10. Vray is the more realistic.....

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