In this tutorial I want to go though some of my techniques for setting up a fast visualization render with Mental Ray inside 3ds Max, with just a little post work in Photoshop.(render time is less than 1 minute for the final render, including a Z-Depth map for the image above).
Software used: 3ds Max 2012, Photoshop CS5.
Setup with very basic components: the main model on a plane, with a Mental Ray Daylight System, an HDR image, one extra lightsource and a Camera.
For this example I created a quick model of a vintage 60s Batmobile Tin Toy from Japan. But as you can see below the same setup just with different objects and materials.
Step 1: The Basic setup
Before we get started you have to select the Mental Ray Renderer here: Rendering>Render Setup>Common (F10)
Import or create the models you want in the scene, together with a ground plane, in my case the plane that makes the table in the final render.
You can move around perspective view until you have a nice angle and just create a camera by pressing shortcut key “Ctrl-C”. This will automatically create a Camera with same settings as perspective view. (You can always change this later.) Then you should end up with something like this:
Step 2: Creating the lights
For this setup I’ve used a Daylight system and one extra photometric light, you can just as easily use two photmetric lighs instead of the fake sun the Daylight system creates, the basic setup is the same. Personally I like the effect the Daylight system give on the overall tone of the image and the shadows.
To create the daylight system go to Create>Systmes>Daylight here:
Once selected you simply draw where you want it in the viewport. Since it’s directional the physical position doesn’t matter, just the orientation.
When you create the light 3ds Max will bring up this dialog box, where you should click yes.:
The Daylight Parameters I set like this, notice I’ve set the shadow softness quite high. For an outdoor scene in strong sunlight you might want to keep these settings on default 1. The samples and softness you can keep on a low setting until you do your final render if you feel it affects your render times too much.
Then you can create the Photometric target light from here:
In my scene I wanted to create the extra light to simulate a regular kitchen type halogen light. But if you are not familiar with the different settings I suggest you try out different ones and see what it does to your scene.
Now your setup should look something like this:
And if you assign a default material to everything and do a quick render you should have something like this:
To control the exposure settings of your camera, go to Rendering>Environment.. or press (8). Here you can adjust how much light your camera takes in. If you are not familiar with Shutter Speed and Aperture… try out the presets first, and just tweak by changing the Exposure Value up and down.
You can get a good instant preview of your scene lights with these viewport settings.
Step 3: Environment map, HDRI
I will use an HDR image to act as the environment of my scene. I used an HDR image of a kitchen interior, but try different ones and find one that match your needs. If you do a simple google search you can fine plenty of resources to get you started.
To use an HDRI texture in 3ds Max, you go here: Rendering>Environment.. (8)
Select an HDR map and make sure it set to Real Pixels (32 bpp). You can also adjust exposure settings but I’ll keep them on default for this tutorial.
Then you have to drag and drop the material to an empty spot in the material editor. Open Material Editor by pressing (M).
In the material you can now set the coordinates of the HDR map to Spherical Environment. Here you can also adjust the strength of the map and blur if you need.
Step 4: Materials
When rendering with Mental Ray I recommend using Arch & Design materials, it’s very powerful and have a ton of options, but also easy to use though a series of simple presets.
We need to get a sense of where we are. So First of I’d just assign a default Arch & Design material to our geometry, because of the reflection we will get a good idea of how our HDR map will affect the scene.
If your model is heavy, it might be useful for you to simply start setting up the individual materials on some spheres while you tweak your settings. In this render I have just made a very simple wooden table and create a chrome and metal material.
For final touches to the materials you should add some textures and bump maps. Use the textures to create the scratches and dirt you want in there. This will really help to get a better sense of realism in the scene.
Here are the textures I used on the body of the car, the bump is set very low, just to add the subtle imperfections that give the impression that the paint is a bit uneven and adding some age.
And here an example of how I setup the material for the body:
If you are unfamiliar with Arch & Design shader, you can start by using a preset that comes close to the type of material you need and then tweak from there.
Pay special attention to the IOR (Index of Refraction) settings for any reflective material you do. Either use the “By IOR” (Fresnel reflections) or setup “Custom Reflectivity Function” as I did in my example. Sometimes you want it to be physically correct, other times you just want what looks good.
Step 5: Final Render
When you are happy with your materials it’s time to render in final quality. No need to over do it, just increase gradually until you feel it no longer does anything to improve the quality.
Here is what I used.
And the render looks something like this:
However, before we are completely done I like to render out two more images, Ambient Occlusion image, and a Z-Depth image, this will give us some nice polishing options in Photoshop.
For the Ambien Occlusion image I wrote a more detailed tutorial here.
And to get a Z-Depth image you simply add that in Render Elements here. Rendering>Render Setup>Render Elements. (F10)
I set the values quite low since my scene is with a small toy, you need to adjust to your scale. You might also want to removed any transparent objects in your scene for this, since it’s not recognized by the render as transparent.
With these settings I get this Z-Depht map and Ambient Occlusion map.
I didn’t use Global Illumination (GI) in my render, for this setup it only takes longer doesn’t actually improve the quality. However, if you need Caustic effects from glass etc. this will bring the realism up a notch.
Step 6: Photoshop and final result
For those final touches that usually takes quite long to render in 3ds Max, and can be difficult to setup, I like to use Photoshop. Here I can easily add depth of field (DOF), Color Correction and maybe some Chromatic Aberration.
To create DOF in photoshop with a Z_Depth map you simply setup the Z-Depth image as a layer mask like this:
Duplicate the layer and create a mask
In layers you select the mask.
You then go to channels and click to activate the mask and copy past the Z-Depth image in there. Afterwards click the eye off again.
You then select the actual image in layers and go to filters and select Blur>Lens Blur..
And here are the settings I used:
And here is the final image, I multiplied 25% of the Ambient Occlusion map in there, added a bit of Chromatic Aberration with the Filters>Lens Correction>Custom
And finally some noise with Filter>Texture>Grain and we end up here: