Forests in maya mental ray.

#661

hi guys, my first post here :wise: :buttrock:
great thread and very informative.

I’m playing around with pfx trees for a few weeks now and it’s damn hard to create some (at least for me) good looking bushes and trees. I’ll scatter them over the grass with the spPaint3d script, which is awesome but at first I want to create many of them for a kinda unique feel.

I tried the magic uv-split-script for the leaf shader but maya just couldn’t handle it? after 15minutes of “working” I killed the .exe , dunno if it’s normal. It was an oak with 800.000polygones. But I’ll try that again.

What do you guys think. Is it better to paint the grass with pfx and edit it as I’d like it or using a custom grass patch as a proxy object?
painting all the proxies over a huge landscape is a pain in the ass and using those scripts that scatter the proxies automatically on vertices/faces/edges take so much time to create them (and since maya doesn’t tell me any progress I don’t know how long it would take on a ~100x100 plane).

anyway here’re two renders.

-matt

#662

I forgot I wanted to post this here after it was done. I did this scene about 6 months ago but forgot about it. I was inspired by the sets they had on Avatar. Really hard to get an accurate poly count as most of it is mib_binary_proxys.

#663

looks gorgeous…

#664

@m0z: I think those both look great! The lack of variation in the leaves is only noticable because you said that’s what you were doing. They look great, if a little uniform in color. Another way to handle this is to use a fractal node and two slightly different-colored texture maps for randomization.

Tastao_Wayne’s script is doing a LOT of math, so you’ll want to let it go overnight. Maybe longer. It will finish, so long as the CPU is crunching away! Also, you didn’t tell us about your workstation, so no telling how long it will actually take.

Same with the scatter scripts. If you’re hoping for it to get done in minutes, you’re probably hoping for too much. Try lettin’ it go overnight or for four hours at least. They work fine for me, but I rarely have such a complex grid to start with.

Another thing you can do is simplify your base geometry for the scatter scripts. Make a low-poly version and scatter 'em on that, perhaps. That’s also worked for me, but of course you don’t achieve the same density. Or of course you can use particle instancing.

Hope this helps.

#665

thanks for the quick answer! I actually have a Q9550 quad 2,8ghz with 8gb ram. I guess I’ll try it again tomorrow :slight_smile: thanks again…

#666

I tried to emmit particles from the surface in order to instance my proxy object on them but I could get a uniform emmition…, I mean, I got a bunch of objects very near one from eachother and some baldness in other places, wich I don’t want.

Is there a way to tell the emmiter to emit particles only were there are no particles at a particular moment?, I mean, I want particles not to be emmited IF there is a particle already there…

#667

Yeah m0z. I was about to tell you the same. Depending on the tree on my 12core here it took even hours. So you might wanna “leaf” it over night :wink: !

Anyway those renders look really cool. I tell you, this thread is one of the most valuable threads i have seen so far here! Really good stuff commin out here!

Keep it up.

#668

haha yeah I think so too. and that F.A.Q. pdf is really great too.
12core and even hours? holy shit, I think I’ll let my pc calculate over night. :smiley:

how did you scatter your 28000 proxies? the grass is very nice!

#669

I used spPaint3d. Took me almost half a day. I didnt care much about overlapping patterns so I maybe could have saved a third by painting more accurately but…it was anyway just a test.
But for grass you might keep in mind if you do the same technique, your target object needs dense subdivisions since the “preview-SubD” does not work. You would get inaccurate scatter of your patterns.

Edit:
@Radon I like the mood in your image! I can see Jake jumpin´ from one tree to the next! :slight_smile:

#670

yep I know. I even painted a big patch of instances in maya -> drop them in a new layer and “detail: bounding box” so my viewport wouldn’t crash. But i can see it anytime, how dense it actually is. Kinda cool

edit:
I’ll stick to painting instances and show the painted ones as bounding boxes. Works best for me.
Here’s a test, I like my soil shader :slight_smile:

#671

Is there some sort of trick to get the leaves to have a cutout? Right now I’m trying a very basic material setup for but can’t seem to get the leaves to take on the cutout opacity. I’m using a mia_material_x_passes with just a color texture and a cutout opacity file connected, but every time I render, I still get the white background around the leaf. See attached images. I’ve also tried using png files with a transparent background but that keeps giving me a black background instead of white.

Thanks for any help.

#672

okay, well, I got it working only because I found earlier in this post an example file someone else had posted of their shading network with a cutout opacity. So I opened that file and network and replace the images with mine and it works. So I’m assuming there is a setting I am missing somewhere but nothing seems to be jumping out at me. Any suggestions from anyone?

I’m now wondering if anyone might be so kind as to post an example file with working mib_twosided node for leaves? I’m having a hard time getting it to work and would really appreciate a working example.

Thanks again

#673

Tried “Luminance as Alpha” in the opacity cutout file node?

#674

Yeah, and don’t forget to turn on something called “use old maya alpha detection style” or something like that in the preferences-> rendering section.

#675

Its the Alpha is Luminance thingy m0z mentioned! You need to check that box!

Edit: m0z…your grass looks good. We tried that workflow aswell and its definitely an option. Thanks for that! :slight_smile:

#676

Thanks everyone! It was definitely the Alpha is luminance. Always something so simple.

#677

well it’s amazing how slow Maya renders the instances. I saved the grass in a second .mb, replaced all the instances with proxy instances (w. LayoutTools), hit render and bam. Super fast, but it seems too me that the FG calculation is just wrong?
The proxy objects are brighter than the instances.

#678

Looks like the grass on the right is having gamma issues

#679

@TheNeverman but both patches use the same material? a little bit illogical for me… :hmm:

#680

Are you using physical sun/sky to light the scene?
If so - where are you tonemapping the scene?