Depth of Field with Mental Ray and After Effects

Depth of Field with Mental Ray and After Effects

Maya 2012 Tutorial


How to Add Depth of Field to Maya Scenes with After Effects



In photography we use depth of field to make some objects in focus and others blurry. Depth of field is accomplished by camera placement and adjusting the camera's aperture.

You can accomplish the same thing in Maya by activating dept of field in the camera options. For more information, see topic, Depth of Field.

In this example we will render a series of images in Maya and apply the depth of field post production in After Effects.


Step One

Create a new project, set your project and save a new scene in the scenes folder. For more information, see topic, Starting a Project.

Step Two

Add three polygon primitives to the stage by choosing Create > Polygon Primitives > Cone, Cube and Cylinder.

Step Three

In the top view, use the Move tool (w key) to move the objects so there is at least 10 units spacing between objects in the z direction.

Step Four

Click the cube, then right-click the cube and choose Assign New Material > Blinn. Repeat the process for the other two objects.

Step Five

Press the 5 key to see your objects in Smooth Shade view. Click the objects one at a time, open the Attribute Editor, then click the Color rectangle to change the object's color. Change the color for all three objects.

Step Six

Click the Render Settings icon to open the Render Settings panel. Choose Render Using: Mental Ray.

Step Seven

Click the Quality tab and choose Quality Presets: Production.

Step Eight

Click the Common tab, File Output section and enter <Scene>_<RenderLayer> in the File Name Prefix box. If you right-click the box you can choose Scene and Render Layer from the pull-down menu. Change the Image Format to Targa (tga).

Step Nine

Open the Channel Box/Layer Editor, then click the Render tab in the lower part of the panel.

Step Ten

Click the cube, then click the Create New Layer and Assign Selected Objects icon. A new render layer is created that only includes the cube.

Step Eleven

Repeat the process for the cone and once again for the cylinder.

Step Twelve

Name each of the layers to correspond with it's content (i.e., cone, cube and cylinder). The new layers should have a green checkmark and the masterLayer displays a red X to indicate it is deactivated.

Step Thirteen

Choose Render > Batch Render from the Rendering menu set.

Step Fourteen

The three rendered images, one for each object, can be found in the project's images folder.

Step Fifteen

Open After Effects and open a new comp by choosing Composition > New Composition. Set the comp size to match your Maya images, then press OK.

Step Sixteen

Choose File > Import > File to navigate to your project's images folder. Click the first file, then shift click the last file and choose Open.

Step Seventeen

In the Interpret Alpha dialog box, choose Straight - Unmatted for all three images.

Step Eighteen

Drag the three images in the correct order from the Project panel to the Comp panel. If the order needs adjusting re-order the layers in the Timeline. The closest object should be the top layer and the furthest object goes on the bottom layer.

Step Nineteen

Select the middle layer in the Timeline and choose Effect > Blur & Sharpen> Gaussian Blur. Adjust the Blurriness value in the Effect Controls panel.

Step Twenty

Repeat the process for the bottom layer in the Timeline.

Step Twenty One

Click the comp in the Project panel and choose Composition > Add to Render Queue.

Step Twenty Two

Open the Render Queue panel, select your project and assign it an Output to: name and location. Press the Render button to render your composite.

Consider Render Passes

With Mental Ray you can take this process several steps further with Render Passes. Render Passes allow you to render separate passes for object properties such as diffuse, specular, reflection, etc. For more information, see topic, Render Passes and Mental Ray.

Can't Find Mental Ray?

If Mental Ray doesn't appear in the Render Settings, Render Using: menu, choose Window > Settings/Preferences > Plug-in Manager. Make sure Mayatomr.bundle is loaded.


Royalty-Free Stock Video at Pond5