Realistic Metal

Mr. Bean

Hello,

So I have a model that has a variety of materials--mostly wood and metal. For the metal I want a realistic, very reflective metal. I want to do it with Mental Ray.

The problem is, when I finally got good lighting enough to make one metal part look good, it made all the other parts look too bright (the wood for example). The only other ways I could make it reflective that I know of would be to 1) have a background, which this model doesn't have, or 2) use an HDRI image. With HDRI, is there a way to use it in Max without any plug-ins or anything? And does it have to be a photo of an indoor scene? And also, is there a different way for realistic reflections?

Thanks

kdm3d

you could use a raytrace material and plug am image into the environment section. THen when it reflects it uses that. just to give that hint of reflection.

Ark

Metals generally have very low diffuse, most of there surface texture comes from reflections.

You shoudn't need a plugin for HDRI's in Max, just stick the .HDR file in the environment slot.

Mr. Bean

I'm using 3ds Max, by the way; I forgot to mention that in my first post.

kdm3d wrote: »

you could use a raytrace material and plug am image into the environment section. THen when it reflects it uses that. just to give that hint of reflection.

Okay, I'll give a try, thanks

Ark wrote: »

Metals generally have very low diffuse, most of there surface texture comes from reflections.

You shoudn't need a plugin for HDRI's in Max, just stick the .HDR file in the environment slot.

Environment slot in the environment settings (the box that comes up when you press the 8 key), or the environment slot in the raytrace material?

Also, for .HDR, does it matter what it's a picture of? For example, can it be an outdoor scene? And how do you get the .HDR file extension?

Sorry for all the questions, but I'm trying to learn Mental Ray much better so that I can get more realistic renderings. And I aim to learn what each thing does, not just follow a tutorial that tells me the settings to punch in.

Ark

Well if you just want to light that particular object with the HDRI, then put it in the materials environment slot, otherwise if you want to light your whole scene with the HDRI, then place it in the environment slot under your render settings.

As for using different HDR's, try to find one that suits what kind of environment your trying to light, obviously don't use one with a bright sky to light say a small room as it will be over exposed unless you reduce the gamma of the image, or vica versa.

Mr. Bean

I see, thanks a lot.

I really appreciate the help, so thank you both for the assistance.

Mr. Bean

Alright, so I'm using this tutorial: [ame]http://www.youtube.com/watch?v=Fm-STdbAdLw[/ame]

The results were gorgeous, but I want the metal to be yellow. How can I do that? Changing the diffuse color doesn't do anything, it only diminishes the strength of the reflections.

Any ideas?

nightshade

if you want some really nice hdri's, look here http://www.openfootage.net/

renderhjs

have a look at the Mental Ray Arc and Design materials, there are some copper, gold and other metal materials there where you can tweak the color.

Mr. Bean

Thanks for the link, Nightshade, I'll definitely check those out!

renderhjs wrote: »

have a look at the Mental Ray Arc and Design materials, there are some copper, gold and other metal materials there where you can tweak the color.

I was using the A&C materials at first, but they didn't look very good since I don't have a background it's reflecting. However, on the part I was having trouble with the copper material looked great. I think it must have to do with the position and shape of the part that caused it to look better with that material than the other parts did. Thanks!

That should do the trick :thumbup:

r_fletch_r

Firstly you NEED something to reflect. you can get some nice HRDIs for free here. if you dont want to see the material in the background put a background switcher in the environment slot and put your reflection map in there. leaving the background slot black.

No plugins are needed to use HDRI files put them into your environment and set their mapping mode to the correct type. most maps use spherical or cylindrical mapping. Some times they come out black. this can be causes by 2 things. 1 your using exposure control and need to increase the output of the HDRI in the bitmap node. or you havent set the black and white points correctly when opening the image.

A&D is the best choice for reflective metal. You get blurry reflections and control of the BDRF Curve/IOR

Staring from the basic A&D Material set the reflectivity to a high value and drop the glossyness to about 0.25. make sure you have 32 or 64 samples for the reflection. Set the IOR to 50.
Scroll down to the BDRF settings and set it to use IOR.

If 1 object is blown out. darken its reflective colour or reflectivity spinner

renderhjs

just assign a reflection map to the environment ([8] key in max, where that black sphere is) - those are basics of max.

kcayton

also keep in mind you're system units and object size. realsitic results from most any materials (A&D are fantastic.) rely also on correct object size. try some of the templates built in to the Arch & Design mat. those are great start points.

Mr. Bean

Thank you r_fletch_r for the step-by-step, I'll give that a try. It definitely sounds like A&D are what I'm going to go for.

renderhjs wrote: »

just assign a reflection map to the environment ([8] key in max, where that black sphere is) - those are basics of max.

I'll try that as well, thanks.

kcayton wrote: »

also keep in mind you're system units and object size. realsitic results from most any materials (A&D are fantastic.) rely also on correct object size. try some of the templates built in to the Arch & Design mat. those are great start points.

Wow, really? I had no idea that affected the material quality; I'll definitely look into fixing that.

Thank you all!