New Mental Ray grass displacement tutorial

[pixelperfectg]

Since the existing grass shader on my site is starting to show it's age, I thought I would share one of my more current methods of displaced grass. Here's the link: http://jeffpatton.net/MR_Grass_displacement.htm

[TheAllusionisst]

Thanks for sharing, a pretty sweet effect for a common need in Arch Viz

[nisus]

Tnx Jeff,

 

Do you know about a limit of how large the surface can be with your grass?

 

Have you experimented with depth falloff to save rendering time on not having to displace at larger distances?

 

rgds,

 

nisus

[nisus]

Hi Jeff,

 

I've checked your new tutorial. It looks great and simple.

I have a question about your render settings though.

 

Why do you set FG max and min radius to the same value? I've read that these should be 10x apart, basicly 1/10th and 1/100th of the scene diameters.

What are your findings upon these values/rules of thumbs?

 

rgds,

 

nisus

[pixelperfectg]

Have you experimented with depth falloff to save rendering time on not having to displace at larger distances?

Yes, at times I use various materials to control where displacement occurs on large objects. No sense in having a displacement calculation when it can't be seen (behind objects), or won't be noticable simply due to the camera distance.

Why do you set FG max and min radius to the same value? I've read that these should be 10x apart, basicly 1/10th and 1/100th of the scene diameters.

As I briefly mention in the tutorial, the settings I used are just for simple/fast preview renders. naturally, the FG won't be super accurate, but for testing, it works well. And since I really only needed a touch of skylight for this scene I just left the FG at my test values.

[yukonhoo]

Hey, new to this forum and just noticed this post. The link that you posted has expired. I was wondering if you still have this tutorial kicking around somewhere?

 

thanks a lot!

[pixelperfectg]

The link that you posted has expired. I was wondering if you still have this tutorial kicking around somewhere?

No, a lot has changed since 2006! Probably a better idea to look for some more recent posts on grass options. Here are a few options to get you started:

 

http://mrmaterials.com/jeffs-blog/101-mrproxy-grass.html

http://mrmaterials.com/resource-central.html?func=fileinfo&id=987

http://mrmaterials.com/jeffs-blog/94-grass-displacement-faq.html

[SoniaTaleja]

great................

I have checked your new tutorial................ good and effective changes.....

 

Regards

Sonia

[yukonhoo]

No, a lot has changed since 2006! Probably a better idea to look for some more recent posts on grass options. Here are a few options to get you started:

 

http://mrmaterials.com/jeffs-blog/101-mrproxy-grass.html

http://mrmaterials.com/resource-central.html?func=fileinfo&id=987

http://mrmaterials.com/jeffs-blog/94-grass-displacement-faq.html

 

 

Awesome! thanks so much Jeff! I found your post with the grass proxy you made - I inserted a few into a test scene and it works beautifully!

Edited February 2, 2011 by yukonhoo