3dats One Project question.

[Sharyn McBride]

I have been working with the book One Project by 3dats. In chapter 6 section 37 there is an exercise to create grass on the red field. I do not have vray. Can anyone convert the vray instructions into instructions that I can use with mental ray in 3dmax to produce the same results. I would like to be able to use this technique in my other renderings. My main problem is with the parameters in the VraydisplacementMod(?) vs the displacement modifier in

3dmax and where to put the noise map into the Texmap(?) Does the displacement modifier in max using mental ray work the same as the VrayDisplacementMod. If not can 3dsmax using mental ray be used to produce simular results?

Thank you for any assistance.

Edited March 30, 2011 by Sharyn McBride

[Brian Smith]

hi Sharyn,

Sorry for the late reply but i didn't personally see this until now. If you post a question on this forum, please send us a link afterwards so we know. If you did already, my apologies, as i didn't see it.

 

You can do the same thing in mental ray using the Displace modifier and placing the map in the Map channel of the modifier, but you have to subdivide the object immensely beforehand. With VRay, you can displace a single polygon into billions of polygons but in mental ray you have to have all of the polygons in place before hand. This makes creating grass like this impractical in most cases because it places too much of a burden on your machine. With VRay, the displacement is handled dynamically, meaning rendered one bucket at a time, and therefore, won't crash your computer. This is another reason why we had to use vray. I hope that helps.

[odouble]

hi Sharyn,

Sorry for the late reply but i didn't personally see this until now. If you post a question on this forum, please send us a link afterwards so we know. If you did already, my apologies, as i didn't see it.

 

You can do the same thing in mental ray using the Displace modifier and placing the map in the Map channel of the modifier, but you have to subdivide the object immensely beforehand. With VRay, you can displace a single polygon into billions of polygons but in mental ray you have to have all of the polygons in place before hand. This makes creating grass like this impractical in most cases because it places too much of a burden on your machine. With VRay, the displacement is handled dynamically, meaning rendered one bucket at a time, and therefore, won't crash your computer. This is another reason why we had to use vray. I hope that helps.

 

That is one (the old) way to do it in Mentalray but not the most effecient way since you can use the rendertime displacement in Mentalray also. You do not need to subdivide your mesh to an insane level just like in Vray. You can do pretty much anything in Mentalray that you do in Vray with the exception of memory issues with tons of proxies. That really sets Vray apart.

 

Your dynamic displacement in Mentalray is controlled by the displacement (Global Settings) under the Shadows & Displacement drop down in the renderer tab. It has similar settings to the VraydiplacementMod controls like the view dependent, Edge Length and Max. subdivs. The Max. Displace settings are the closest thing to the water level parameter in the VraydisplacementMod I think... not completely sure but it looks like it clips the displacement to the specified height. Vray keeps these settings in a modifier which allows you to assign the displacement per object.

 

Just use an Archdesign material and plug your map into the displacement slot and that's it. Take a look at the link to get more of an explanation from Jeff Patton's post.

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

[Brian Smith]

I don't use mental ray, so thanks for the info...good to know.