Forests in maya mental ray.

#481

Hi guys. Im really sorry to be asking things that seem to have already been covered in this extensive thread. Im new here but have been using maya for a few now and having a nightmare with my scene.

I just cant seem to get double sided shading to work on my leaves, I’ve tinkered with both the sampler info & Condition method and the mib-twosided method and really cant seem to get my head around how all the connections are made.

I hate to be a pain in the butt but if anyone could kind of go through things step by step with me I would really appreaciate it. Using the mib_twosided method I managed to kind of get it to work, but can’t figure out how all the other information is passed through or connected i.e the alpha, bump, reflection etc.

If it any help im using maya 2010 and rendering with mental ray.

Cheers all. :slight_smile:

#482

shaun, I was also curious about what you are asking, so you are not the only one. When I tried to replicate the network in the screenshots, it seemed like the 2sided mat only dealt with 3 channels, so was it only used for one of the material attributes like translucency? or color?

I guess you could use one for each texture type, but I’m sure there’s something I / we are missing.

#483

Well it certainly has me stumped for now. I think I might just try a sampler node with a switch utility to simply switch the normal direction depending on the camera. Wont be very realistic as will just be the same texture, ref, etc on the underside of the leaf. But I think for my kind of scene I may get away with it. Fingers crossed it works for me :wink:

If you do manage to figure it out let me know. I shall continue to tinker also when I get the chance as I really want to suss this.

#484

You must to connect one mia_material_x (result) to the front slot of the mib_twosided, and another mia_material_X (result) to the back slot,

connect the mib_twosided output to the shading_Group Material Shader and one of the mia_material_x output to the shading_Group Shadow Shaders (mib_twosided doesn’t transmit the transparency)

#485

in first place i tought im missing something but when i saw screenshots of shading networks it looks like nobody is using mr shadow transparency node for leaves … its exelent for this instead of using actuall transparency and still veeeery different from just coloring the shadow of light itself (in light settings),
cause when using shadow transparency node u dont get just overall shadow transparency, u get decayed effect as it passes more and more leaves and u will end up with veeery nice and smooth SSS effect specialy when u combine it with FG at the end. ofc u keep up all translucency settings but u kill transparency so u dont have ghosty-leaves if u have some heavy closeup

Ivan

#486

mia_material_x does this automatically.

#487

hmm not really,

(correct me if im wrong)
i tested it and what mia mat x does is something similar to fake as if u would tune up shadow color on light and theres no decay effect in it neather.

try to put few planes on top of eachother, spot light on top , and watch decaying of shadows with matX settings and then with shadow transp

#488

LOD for mental ray!!

#489

6 placeholders !

#490

how can i find the order of the shaders … pls help !!!

#491

Select the original object after combine it, open the atribute editor, and look into the upper tabs to see the order

#492

Hi,
Here my technics to have multi-shader on one mesh.
Work with proxy, geometry cache, and other. It is clean and without “per face shader”.

http://deex.info/wordpress2/2010/03/multi-shaders-or-textures-in-one-meshobject/

Thank.

#493

Hey Roberto! I saw that you posted your script, but it seems as though the download link is broken. How are you coming along on it? It already looks amazing and I’d love to try it out. Any chance you could upload it?

#494

Awesome thread guys!! Although its been a couple hours I’m currently still reading and I’m at the 19th page. Just had to comment on such an amazing thread. For about the past 3-4 years I have searched and searched everywhere on how to create a large coverage of grass for my scene/building to sit on as my camera animates around it. I believe I have finally found the right spot to my problems as far as grass. I just hope as I finish this thread I will be able to create my grass without huge render times. Also wouldn’t mind coming across perhaps some sample scenes of grass just to see how everything is connected.

Thanks to all who put such brilliant knowledge and effort into all this.

Ok, well I just finished up. What a bummer to see that this thread kinda died off. And for the people who need help, it seems as if those that are really experienced here pretty much are not as much concerned with it anymore.

#495

Ok, well I just finished up. What a bummer to see that this thread kinda died off. And for the people who need help, it seems as if those that are really experienced here pretty much are not as much concerned with it anymore.

I know you weren’t trying to insult us. The reason the thread “died off” was simply because we all achieved what we were trying to: more realistic plants and in more realistic quantities. There are plenty of samples of grass and trees throughout; did you miss the more grass-specific pages?

If you have a question, just ask! We can’t be “concerned with it anymore” if you don’t let us know what kinds of problems you’re having.

As for render times, using instancing you’ll experience a similar RAM usage with one instance as you will with thousands, roughly. But speed itself is determined by the complexity of your MR settings and your BSP situation, as well as raytracing complexity/depth and other elements of your specific scene. If you play with MR a bit, you can get your rendertimes down tremendously. There are about 489,003 ways to do this. Feel free to ask questions, if yours are still unanswered!

#496

can u share u r grass material parameters and lighting teqniques !! did u use mia_exposure photograaphic !!

#497

InfernalDarkness- Not at all! Im here to learn these things as well as everyone else. Why would I try to insult you or as you say “us”?

I think you may have mis-interpreted what I was saying, or I just used the wrong choice of words. Either way, no harm or insult intended. Sorry if it sounded that way.

I just think the work here that I have seen is the most amazing vegetation I have EVER seen done with the use of maya MR. I had only thought the way to get these kind of results were to use something like Vue or Bryce. This stuff is really awesome stuff. And if I could get a lawn of grass just like visua created, I would be the most grateful person.

#498

Well it seems like I just have to put together a tutorial on how to make decent grass
in maya/mental ray one of these days :slight_smile: I’ve received quite a few messages/mails regarding
my grass, but I don’t really have the time to answer every single one of them since I’m swamped at work and so on. Be patient and hopefully I will find the time to write a tutorial on the subject (but probably not until early august).

Cheers

//NIC

#499

3DRenderer, no harm done. Just couldn’t think of anything we didn’t go over, although it’s not organized like Visua was talking about, but a few different peoples’ workflows and ideas. I apologize if my response also seemed scathing.

I had only thought the way to get these kind of results were to use something like Vue or Bryce.

You should be able to leave those guys behind, with Maya/MR and decent hardware (64-bit, 4+ GB RAM). I haven’t used either for nearly a year. Bryce has great texturing and Vue has its perks, but the level of detail and realism you can achieve with MR blows both of those progs away, really.

That said, you’ll have to make your own libraries for plants which are “ready”. And that’s taking me forever, myself!. It’s more difficult to be quickly creative and just “sketch” scenes out when you have to slave over each plant first, but the results are well worth it…

As for your grass, Visua’s was much better than mine. Give him some time and he’ll be able to help more, I’m sure! But don’t hesitate to make your own tests and tweaks… Try and keep trying. That’s all we did, here!

#500

I will also try to complete my “Forest thread Resume” when I have some time. Now it’s more or less on half of the thread.
Off course I also would enjoy a complete Visua tutorial :slight_smile: