Ok you've got all the materials down, we're going to set the scene up for rendering, create an ambeint light with no intensity, and make it cast shadows


Now create a point light with no intensity, and make it cast shadows (these will be our shadow makers, we're giving them no intensity to disable the default lighting, and the reason why we're using an ambeint light and a point light is because, a point light creates hard shadows, and an ambeint light creates soft shadows, you combine the two and it gives you a nicer shadow)


Now we've got the lights, go to render globals Select mental ray out of the drop down menu, in the common tab of mental ray, change the size to any size you want, I chose full 1024, now over in the mental ray tab apply these settings:

Min sample Level 1

Max sample level 3

Turn all the raytracing sliders to maximum except shadows, or you could if you like

Final Gather, turn final gather on by clicking the final gather check box, give it 500 final gather rays

Image based lighting, click create, if you do not have an HDRI map you can download one from my DeviantArt account, by clicking this click http://www.deviantart.com/deviation/24226891/ I used the APT probe wich is included in the .rar file. you can choose to either set the mapping to spherical or angular, angular tends to look a bit better. I chose sphereical

Here is the final result



This is what yours should look like if you used Angular mapping on your HDRI, as you can see it's a bit brighter but the shading on the gear looks much better

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DoF (depth of field)

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Depth of Field is basicly a "gauss" blur if you're a photoshop user you should know what that is, it adds ALOT more realism to your renders, for this you will need multipul objects, I would go into wireframe mode, (this is a high poly gear) and duplicate your gear, and place it further away, or maybe if you want you can do a chain of gears enterlocked. Once you've placed/duplicated your gear, select the one you want focused on, then go to display>Heads up display>object details, find the distance from the camera over to the right on your new HUD, either remember that number, or write it down in note pad and copy it. Now select your ground plane, and hit the right arrow until you come upon the prespective camera "perspShape" Scroll down and click the mental ray tab, click the checkered box next to the text area that says "Lens Shader" next to it. Scroll down to where it says lenses, and click "Physical_lens_dof" Now in the plane text area, if you copied the distance from the camera, paste it, and put a - next to it, if you rememberd it type it in and put a - next to it, (a - will work in most cases if it doesn't, change the - to a +) and render!

Hope this was helpful! Good luck with your 3D
http://micah.noobgrinder.com/geartut http://micah.noobgrinder.com http://thunor.deviantart.com