This is part of a beginner's learning guide for Maya. Tutorials in this series are short but cover a single topic in each one.
There are two ways of making shadows in Maya: depth map shadows and raytrace shadows. Raytrace shadows take longer to render, but are higher quality. For raytrace shadows to appear, raytracing should be enabled in the renderer.See Raytracing.
Depth Map Shadows
To enable depth map shadows on a selected light, open the attributes editor (window>attributes editor), click on the shadows tag and check Use Depth Map Shadows.
Resolution - The higher the resolution of the depth map, the higher quality the shadow will be. This will increase render time.
Use Mid Dist - This is checked by default and, when unchecked, it will create lines on the image. Not recommended to uncheck.
Use Auto Focus - This is checked by default. When unchecked, you will need to manually set the width of the focus.
Width Focus - When set to 1, the shadow will be hard and crisp. Set to 100, the shadow will appear to be blurred or obstructed. This is for directional lights.
Focus - The higher the value the more blurred the shadow will become. This is for all lights except the area light which does not have these attributes.
Use Light Position - This attribute is referring to the width focus. It's a good idea to check this.
Filter size - The larger the filter, the softer and higher quality the shadow will be. Render time will increase.
Bias - Sets the bias.
Fog Shadow Intensity - This sets the intensity of a shadow the light will send into fog, if your scene has it.
Disked Based Dmaps - When using depth map shadows, you can save the map it creates for shadows on your hard drive and use it for the next rendering. When set to Overwrite existing Dmap(s), this will rewrite a Dmap on your disk. When set to Reuse exisiting Dmap(s), it will use the last saved Dmap. Note: Dmap stands for depth map, not disk map.
To enable Raytraced shadows on a selected light, open the attributes editor (window>attributes editor), click on the shadows tag and check Use Ray trace shadows.
Light Angle - When this attribute is increased, the shadow will appear softer. It will be grainy if you don't increase the shadow rays.
Shadow rays - Increasing the shadow's rays will increase the quality of the shadows. It will also increase render time.
Ray depth limit - Sets the ray depth limit. When you find problems with a shadow in rendering, increasing the ray depth can fix it.