mia_material for realistic leaves

#141

I´m creating a photorealistic banana tree at the moment, but i have my problems with the lighting and the colors. I made video all of my settings and textures so that you can see what my problems are: http://www.youtube.com/watch?v=mgr1AoEM8ME

#142

@ColonelMillerSG21:

A couple things… But thanks for the video! Really sums things up much better than back-and-forthing our questions about your settings.

  1. I think it may help in the long run to set up a Blinn first for all your stuff like this, so you can see in your Viewport how it’s looking a bit better. Attach your mia_mat_x in the shading group like you are, but you’ll have Viewport visibility which can help pre-correct color issues sometimes. Just my flow, obviously you don’t have to do this and it won’t affect your mental ray rendering…

  2. Your cutout opacity map should be a standalone image map for easier diagnosis. It appears you have it connects to an alpha channel in one of your image files? Chances are, there are some dark but not-quite-black sections in this image causing this. If it’s clean, in the File node color rollout check “Alpha is luminance” and maybe that will help? Turn off filtering for that file node, perhaps?

  3. Are you using Fresnel falloff, for your BRDF? Probably should be, but if that’s not working well for you then try tweaking the BRDF manually. Alternatively, you can use Fresnel with very high IOR in the Refraction section to define and brighten up reflections.

  4. Is it too reflective? This may be a result of your image map going into the reflectivity channel. Try disconnecting the map and using a Reflectivity of .4 or so, glossiness around the same, to dull up those highlights. Or did you mean it wasn’t reflective enough?

I think it looks pretty good, personally!

#143

  1. Thanks, this works very good :slight_smile:

  2. I had the same probleme with 4 different alpha maps (mixed psd and also alpha maps without color information). I tried “Alpha is luminance” before, but that doesn´t work too. But the anti aliasing tip works, thank you very much for that :slight_smile:

  3. Yes. I try the refractive tweaking.

  4. No, i´ve tried that before. The color and brightness of the leaf is the same:

#144

Do you have access to the image file itself? (I’m assuming you do…) If so, maybe just dial down the brightness and contrast a bit in Photoshop or something? I have to do this to my wood textures all the time, to match clients’ existing kitchen cabinetry, for example. I also did this with some flowers last night. Sometimes it’s nice to have that kind of control, too - update one file and control all the related nodes in Maya, obviously.

The leaf’s diffuse does seem a bit washed out… It appears you’re doing it all linearly, but my next question… If so, are you also using the Render Setting’s “Color Management” too? If you’re using that, you don’t need the gamma correct node in this leaf’s network at all. That check-box covers all file textures.

What connection are you gamma-correcting in this network? The reflection, or just the diffuse color? If you’re using file textures, you shouldn’t have to gamma-correct any connections (so long as Color Management is enabled.) But I’m really not the expert on linear lighting. Hope one of these ideas helps.

#145

ColorManagment! That was the crucial missing point. Now the view of the Textures in PS compares a little bit better with the final render.
http://imageshack.us/f/441/bananaj.jpg/

#146

It looks better now, but i still have a color managment problem:

http://www.youtube.com/watch?v=Tbhb61oUAX4

#147

Do you have an exposure node attached to your rendercam?

#148

I think it’s more of an issue with your texture map itself, actually. Note that it has many highlights already. I know it’s not easy to find or make textures without highlights, as we often need a camera flash “in the field”, but perhaps a nice clean scan or lighting setup without a flash would produce a better texture map?

Trick is to not get any speculars in your photo-textures. I think what’s happening is the raytraced specularity (reflections) are screening against the photo’s specularity, and thus producing the blown-out areas you’re seeing, as well as blowing out the dark areas into the pixelly-mess you displayed in your video.

Perhaps save a test scene version of your scene, and try it with these basil leaves I made last summer, just as a test?

Diffuse:

Bump:

Alpha:

There’s still some specular in the diffuse channel, but not nearly as much as we’re seeing in your banana leaf texture. No actual “whites”. And I don’t think this is a perfect or “great” texture example (my basils) either, just a test to see if it helps?

#149

Thanks InfernalDarkness, that was very helpfull :slight_smile:

That´s the actual status (still some problems):

http://www.youtube.com/watch?v=JwLQ9PM3lH0

These are two of my new maps:


#150

Regarding your color map there, is that the file you’re using for the diffuse channel? If so, be sure to overpaint the colors beyond your alpha (cutout opacity) map. You can kinda see the white edges somewhat in your renders, due to the image node filtering process.

Are you using mipmap with a filter strength of .2 already, for your diffuse node?

#151

Not the final version. When i´m using vue, i always give it a green background, in a smiliar green. I wanna do it the same in Maya.

Are you using mipmap with a filter strength of .2 already, for your diffuse node?
No, why? (I´m using the standard filter)

#152

Then that would be the quadratic filtering at a strength of 1? Sometimes this can wash out your details a bit too much, and it certainly reduces clarity. Your maps look really good and perhaps a lighter filter would bring out more detail in the renders. I generally end up with a mipmap between .1 and .5, depending on the texture I’m working with, but of course feel free to play with it and do whatever looks best!

#153

Just a note: I notice your cutout map has anti aliased edges. I did a test in vray some time ago, one render where the leaf alpha had AA-edges like yours and one where it was only black and white, no shades of grey/AA. Render times were 0.50 and 2.55 respectivily. I don’t know if it works the same in MR, but just in case you should probably get rid of the AA to get render times down quite a bit. You wont notice the loss of AA when rendering.

#154

Much better, thank you so much guys :slight_smile:

That’s how it looks now: http://www.youtube.com/watch?v=_-rLp8W9OJs (1080p)

I´m still workin on the specular and the translucency.

#155

Hey,

I made a displacement map to get more details and to improve the highlights, but still problems and more problems. I think the last problem is a lighting problem. I made a small video to show it to you:

http://www.youtube.com/watch?v=Qn5Ef_oIlE4

#156

You’re using the mia_material_x for this leaf, correct?

By default, the mia_mat_x has enabled “fake specularity” which is similar to the Blinn and Phong in how it renders. Specularity itself does not exist as an actual visual effect; it’s simply a function of the reflections of light across a surface and the angle of incidence and also the wetness of the “camera” (your eye). Thus, “fake specularity” where the shader tries to mimic this effect based on the direction of light hitting the geometry and the angle of the camera in relation… But this is not a “physically correct” method, just an approximation.

In the Advanced rollout for the mia_mat_x, there’s an attribute called “Specular Balance”. Default is 1 (fake specular) and 0 is “reflectional specular only” basically. At 0, you need physical lights in the scene to make it work, but you should be using physical lights anyway with mental ray. The sun/sky will work, for example, but not a Maya-native directional light unless a mental ray light shader is attached.

Play with the Specular Balance a bit and see if that helps?

#157

Yes i´m using the mia_X material. The Specular Balance didn´t work very well:

http://www.youtube.com/watch?v=sXUzkcgj4SI

#158

To be honest, I think your leaves look fine. Depending on the final image/animation, you can probably just handle the rest in postwork with Photoshop or your animation compositing application. Without a scene to judge their realism from, it’s hard to say what else you could do.

One thing I was curious about, why is it black in the viewport? I tend to like having my viewport show my textures, so I can at least get an idea how it’ll look before rendering. And you can quickly check your “fake specularity” by pushing 7 as well (render viewport lights).

#159

Thanks :wink: Well, i don´t think that i can fake the specular highlights in Photoshop, but you are right.
To the viewport: Most of the time it´s turned on, i swear :wink: I had a little perfomance problem because i was rendering with another program in the background.

This whole Plant thing is for a videotutorial on my tutorial channel. That´s the reason why i wanna make it perfect.

#160

I finished the leaf. I will render it with multipass.
But before i render it, i want to add some waterdrops. I created some spheres with a mia material and refraction turned on, but the water is black when i take it on the leaf(It works on all other polygonal objects):

http://www.youtube.com/watch?v=CT1bF-Nw--0&feature=youtu.be

Edit: Problem solved