1. First, select all the models in maya. On the layer layout, select the rendered layer, as shown in the green box below. Click the small icon in the upper right corner of the render layer layout, then click Create a new layer and specify the selected objects, as shown in the order in the red box in the following figure.
2. Right-click the newly created layer, and then click Layer Properties to open the Properties dialog box, as shown in the figure below.
3. In the Layer Properties panel, click to open the preset for layer rendering, and then choose the Timing command. At this point, all objects in the layer will be added with an AO shader set by maya software.
4. Click the triangle behind the Output Color node under the Surface Shader.
5. Increase the sampling rate below several points of the shader, usually 64 or 128. If it is higher, it can be adjusted to 256, and the maximum value cannot exceed 5 12. The larger the value, the faster the rendering speed will be, and the effect is shown in the following figure.