Step 2: Customizing lines in JiffycrewLineManager

In step 1, we setup a line drawing scene by adding JiffycrewLineManager blueprint to the level. Let's evaluate options in the panel and see how the line drawing changes with different values.

The JiffycrewLineManager Detail Panel

JiffycrewLineManager is an unified control tower of line drawing. You can turn on/off lines, change blending modes, change line application mode, change line property of different lines types, etc.

JiffycrewLineManager Detail Panel

Option	Description
Show Lines	Switch to turn on/off lines
Multiply Line Color	On: The line colors are multiplied with scene rendering. Off: The line colors are linearly interpolated with the scene color
Augment Scene Color	On: Line + Shading Off: Line only + Solid background color
Use Custom Depth	On: Lines are drawn on objects whose "Render Custom Depth" is on Off: Lines are drawn on all the visible objects
Use Depth Adaptation	On: The line width and other properties are adjusted by depth to preserve appearance. Off: Line properties are not affected by depth. All the lines have the same line property.
Silhouette/Crease/ SuggestiveContour/ SuggestiveHighlight Line Enable	Switch to turn on/off each line type.
Silhouette/Crease/ SuggestiveContour/ SuggestiveHighlight Line Width	Line width of each line type.
Silhouette/Crease/ SuggestiveContour/ SuggestiveHighlight Line Color	Line color of each line type
Silhouette/Crease/ SuggestiveContour/ SuggestiveHighlight Line Threshold	Line threshold of each line type. Higher value makes less pixels of such line type is detected.

Go into play mode first

Jiffycrew Post Process Line uses 200% supersampling to draw anti-aliased lines. Because the supersampling effect is only enabled in play mode, the lines in the editor and play mode may have different looks. To see the final rendering quality while editing, we will modify parameters in play mode. Please click play - selected viewport and then click JiffycrewLineManager.

The parameters changed in play mode can be saved by JiffycrewLineManager Actor - right click - Keep Simulation Changes.

Setup camera position

To see lines on different depth, please move your camera to similar location shown in the image.

Removing lines from the floor (Using Custom Depth)

In the current result, the lines are drawn on the floor boundary. To remove those lines, turn on UseCustomDepth. Then click three character (actually skeletalmesh) actors, and turn on their render custom depth switches. See that lines are drawn only on characters.

Setup line only drawing

We will now get in the line only drawing mode. Turn off augment scene rendering.

Depth adaptation test

We will now see how depth adaptation makes rendering of far objects different. Turn off depth adaptation and see the result.

No depth adaptation

Now, please restore depth adaptation switch and base depth to default values for further examination.

Setup thin line width

We will now make line thinner. Change all line widths to 1 to make thin lines.

Enable suggestive highlight lines

Suggestive highlight lines are emissive lines that are drawn on the view-dependent ridges on the surface. By combining with suggestive contours they are effective to exaggerate the shape. This line is by default turned off, because emissive lines are rarely used in usual artistic line drawing. But having it often makes the scene more stylish and conveys shapes better. Try to turn it on

Color lines

Make silhouette line color to (128,0,0), crease line color to (0,128,0), suggestive contour color to (0,0,128), and suggestive highlight color to (128,128,128). and see the result.

Please also try to turn/on off line enable switches and adjust line threshold sliders to see how the lines become different