Render Layers

Render Layers

Maya 2012 Tutorial

 

How to Render Layers to Composite Layers in Maya

 

 

Render Layers allow you to render your objects one at a time so they can be reassembled in a compositing program (i.e., Photoshop for stills and After Effects for animations).

In this example we will create a scene with two objects and a light. There will be three rendered images, object one, object two and the shadow cast on object two.

This method is used to give you additional flexibility in creating your final image. Since the image is broken into a separate layers, each layer can be adjusted in post production without having to re-render the scene in Maya.

The methods described in this topic work with Maya Software Rendering. For Mental Ray it is a completely different process. For more information, see topic, Render Passes and Mental Ray.

 

Step One

Add a polygon plane to your scene by choosing Create > Polygon Primitives > Plane. Make sure to start and set your project. For more information, see topic, Starting a Project.

Step Two

Add a text object to the scene by choosing Create > Text. For more information on creating text objects, see topic, Text Object.

Step Three

Add a spot light by choosing Create > Lights > Spot Light.

Step Four

Position the light in the scene so it illuminates the text object.

Step Five

Select the light and open the Attribute Editor. Activate Depth Map Shadows by opening the Shadows and the Depth Map Shadow Attributes sections. Click the Use Depth Map Shadows checkbox.

Step Six

Render your scene by clicking the Render Current Frame icon to make sure your light and it's shadows are working correctly.

Step Seven

Select the light and the text object and open the Channel Box.

Step Eight

In the Layer section (lower portion of Channel Box), click the Render tab.

Step Nine

Choose Layers > Create Layer from Selected. This creates a render layer for the text object and the spot light.

Step Ten

Name your layer text.

Step Eleven

Choose Layers > Create Empty Layer. Rename your new layer plane.

Step Twelve

Choose Window > Relationship Editors > Render Layers.

Step Thirteen

Click plane in the left column and click the light and plane object in the right column. This is just another way to accomplish the same goal as Step Nine.

Step Fourteen

Right-click the Master Render Layer and choose Select Objects in Layer.

Step Fifteen

Click the Create New Layer and Assign Selected Objects icon in the upper right corner of the Layer panel.

Step Sixteen

Name your new layer shadow.

Step Seventeen

Click to select the shadow layer. With nothing selected in the scene, right click the shadow layer name and choose Attributes.

Step Eighteen

Open the Render Pass Options section, deselect Beauty, then select Shadow.

Step Nineteen

Open the Render Settings window and select an image format that supports alpha channels (i.e., targa or tiff), then Batch Render your images. For more information, see topics, Rendering an Image and Rendering a Movie. Once rendered, the three images can be found in the images folder, inside another set of folders labeled to match the Render Layer names. The images can now be opened in Photoshop or After Effects for final compositing.

Step Twenty

If you are compositing in Photoshop, double-click the layer icon to convert your layer into a transparency layer. Command click (PC - Ctrl click) the alpha channel to make a selection. It can be used as a layer mask by clicking the Layer Mask icon.

Step Twenty One

By using render layers you have editing control of the text, shadow and plane.

Where's My Shadow

The shadow is hidden away in the alpha channel. As you import into After Effects, the alpha channel is automatically loaded. For Photoshop you will need to do a little manual tweaking (see Step 20).

More than Just Beauty and Shadow

Using this method you can also separate Specular, Color and Diffuse images by selecting the checkboxes in the Render Pass Options.

For clarification, Beauty means all of the images combined. The Diffuse pass doesn't include reflections.