View Full Version : Metal Textures


Dmorcos
04 April 2013, 08:23 AM
Hey guys, so... I'm a cinema 4D user (yay for workflow!). One of my biggest if not THE biggest challenge is metal textures. For almost a year now, i've been trying to nail it with that cinematic, realistic look but I just can't get it. It will look unrealistically bright , specularity is off, bit map isn't that great. To show you what kind of metal i mean--here's a good example: http://forums.cgsociety.org/showthread.php?t=981866&utm_source=cgsociety&utm_medium=cgchoice&utm_term=981866

here's another example:

http://forums.cgsociety.org/showthread.php?t=926613&utm_source=cgsociety&utm_medium=cgchoice&utm_term=926613

Pay attention to the ground. Now I know that external rendering plugins were used to enhance the final product. So my question is: What is it about those metal textures? There are obviously steps I am not taking that I should be taking. Im not asking for a tutorial. But what are the steps?

Magnus3D
04 April 2013, 07:41 PM
First of all, if you would have bothered to scroll down a little there is a texturing and a Cinema4D section you could have asked this question in instead of here. That's why they are there..

However, regarding metals and metaltextures in general. Those types of surfaces reacts to light in different ways, naturally is varies from metal to metal, metal ages differently and accumulates dirt differently from eachother and then you have natural oxidation of the surface which adds yet another twist to how the surface reflects light.

Your question is not very specific in terms of which exact metalmaterial you want to reproduce but looking at those exampleimages you linked to you need to have a good lighting to start with, then a good enviroment for the metal to reflect, then a bunch of various textures which controls reflectance, dirt, specularity, diffuse, roughness, fresnel and more.. plus correct settings for the metalshader.

Good luck!

/ Magnus

leigh
04 April 2013, 07:48 PM
Metal is all about reflection. Without good reflectivity maps, you simply won't get great looking metal surfaces.

ThePriest
04 April 2013, 08:45 PM
Here's a video to show you how to generate good specular maps. Consider it a starting point, though I'm not fond of all the techniques he uses.. http://www.youtube.com/watch?v=5Gqp4bNJ52M

A C4D material is limited to a single reflection map and has no texture control for blurriness. You can of course stack materials, but the workflow is a little tedious.

VRay on the other hand has 5 channels for mixing up specular/reflectivity layers and offers a great deal of control for anisotropic effects and varying degrees of blurriness in the metal.

There's also various plugins to help you define areas where the secondary material might be placed. AOB Curvature shader, which can be useful for picking out edges for a kind of reverse AO look. Tools4D topology mapper, which provides a vertex map based on the parameters you chose and is also very beneficial for stacking effects.

So with a combination of texturing skills, knowledge of how to mix up you layers, good experience generating procedural maps, you can achieve great effects in C4D and even better with VRay.


Tools4D topology mapper. Showing a vertex map which can be used as a mask.

http://www.corenavigation.com/cgtalk/topology.jpg

AOB Surface shader. Useful for picking out details. Especially in metal objects.

http://www.project1media.com/cgtalk/SurfaceCurvatureShader.jpg

I'm not a great texture artist, so I've learned to get by with a variety of cheats.

Neither shot has an actual texture map. All procedural and layered.
http://www.corenavigation.com/cgtalk/combo.jpg

musashidan
04 April 2013, 02:44 PM
Here's a metal shader I did several years back. As Leigh mentioned: It's all in the reflectivity. And also the bump map breaks it up nicely. The image below is lit with both .hdr environment lighting and a direct 3-point setup. The lighting is obviously very important aswell and I would put much less emphasis on the diffuse map in terms of contribution to the metallic quality of the shader depending on the type of metal and it's adherence to the laws of energy conservation.

https://www.cgsociety.org/cgsarchive/newgallerycrits/g13/155913/155913_1260363172_large.jpg

CGTalk Moderation
04 April 2013, 02:44 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.


1