User Guide > Composite > Workflow   

Layering Clips

The layering of clips is the essence of compositing. In Houdini , you can use the Layer COP to bring together several operations. Using the Viewer pane, you can create several clips then interactively select and layer them. This results is a network of composite operations that feed into a Layer COP.


1. Setup

Select Settings > Composite Project. Set the Resolution to 512, 512. Click Accept. These Project settings will affect how new clips are created.

Select Network > Compositing (COP) from the Viewer pane menu. This takes you to the top level of the img folder. Press i to go into img1. You can set up several composites within one scene file. Each one would need to be set up as a separate Image Network.

2. Import a Ramp Background

In the Viewer pane, press tab > Generator > Ramp. This creates a Ramp COP that has a resolution of 512, 512.

In the Viewer pane, click in the middle of the screen to add a third ramp point. Alt-click on the Points icon and change its color. Repeat for all the points. In the Parameter pane, click on the Ramp tab and set Rotation to 30.

3. Create a File Image

In the Viewer pane, press tab > Generator > File. MMB-click to accept this and add it to the Viewer pane. Now you can see both COPs. Use the MMB to zoom out. Use the Link Scrolling button to zoom them together. This File COP is referencing the default butterfly image which you will use in this lesson.

4. Create some Text

In the Viewer pane, press tab > Generator > Font. MMB-click to accept this and add it to the Viewer pane. Again the node is created at 512x512 to match the Project defaults. Now you can see all three COPs in the Viewer pane.

In the Parameter pane, change the entry in the Text field then choose a Font that you like.

5. Layer the Three clips

In the Viewer pane, press tab > Generator > Layer. LMB-click on ramp1 to choose this as the background then click on font1 and default_pic as the foreground layers. Text will show up on the clips to indicate they have been chosen for layering.

MMB-click to accept. The layer1 clip is placed into the Viewer pane alongside the original operators.

6. Reorder the clips

In the Parameter pane, you can reorder the clips by clicking on the up arrow found on the left of each layer's listing in the Input Operator list. The top operator is the background. The other operators on the list have arrows and are designated as Layer 1, Layer 2... If you click on the Transform tab, there are sub-tabs for each of these layers.

Press the t key in the Viewer pane to focus on the layer1 clip. The other clips are shown as tabs along the bottom of the pane.

7. Render out the Results

In the Network pane, select Network > Outputs. Press tab > Generators > Composite. In the Parameter pane, set the COP name to layer1 then click the Render button to render to an mplay window. You can also set up the Output Picture to render out a sequence of images.