Autodesk 62205-051408-9001 User Guide - Page 862

33 Advanced Topics G-Buffer Builder Example: 3D Fog In the following example, we will add a 3D Fog filter to footage of a sunset. To do so, we must create a grayscale Paint operator which will be used to create the Z Buffer. G-Buffer Builder example: 1. Open the required footage into a new composite. For this example, we will use the following .png file. The Z Buffer dialog appears. You will use this to choose the operator whose image information you want to use to create the Z Buffer. 2. Add a Paint operator. 3. In the Paint operator, create a grayscale gradient over the image to represent the Z depth information. Dark areas of the gradient will indicate the background of the image, while light areas will indicate the foreground. 7. Pick the Paint operator, and then click OK. Note: In the Schematic View, you could also connect the output of the Paint node to the secondary input of the G-Buffer Builder node, and then choose New Z-Buffer. In the G-Buffer Builder controls, Paint appears in the Z Buffer Operator Input button to indicate that an input source has been selected. 4. In the Schematic view, right-click and choose Add Operator | 3D Post | G-Buffer Builder. 5. Connect the output of the Footage node to the input of the G-Buffer Builder node. 6. In the G-Buffer Builder controls, click Z Buffer Operator Input button. 846