Want to make a glowing ribbon, like this...

Question

I am trying to find the right combination of filters and effects to apply to a shape to get the glowing ribbon effect as shown below. Any advice would be appreciated.

Answer 1

Linear Light works well. [**see below for opacity]
To do the ribbon effect:
Add a Camera (go into 3D) [or reset an existing camera to the default view]
create a rectangle that's about 4-8 times taller than wide
create a bezier line (create bends here and there [start with 2 like a sine wave]) > type Return to "finalize" the line (otherwise Motion will try to close the "curve")
set Brush type to Image and drag the rectangle onto the Brush Source well ["hide" the rectangle if it doesn't automatically do so]
set the Brush Width to 100 to start (you can play with this setting later)
drag the spacing slider until all the gaps are closed (think you can go all the way down to 5% - you don't want any telltale vertical "overlap" lines either)
set your brush Color (optional - see Color over stroke below)
In the Properties tab, rotate the bezier line 'X' 90 degrees [or -90 depending on how you want the ribbon to be arranged in z-space]
In the Shape tab >
In the Stroke panel > check Local 3D
                           > Check Align Brush Angle
turn down the Brush Angle disclosure triangle to reveal the XYZ
for X set to -90 (my habit; 90 will probably do, but for many other types of these 3d transforms it is usual to rotate properties X one direction and the shape orientation X the opposite)
To rotate/position this ribbon in space, select the group and use the group's params
after positioning, you can go back into Shape > Stroke > Stroke Color Mode > Color Over Stroke
you can use this feature to create "lighting" effects for the curves by lightening/darkening your basic color tints. You can also adjust the **opacity of the ribbon with the opacity controls on the Color Over Stroke gradient control.
Some caveats:
brush strokes are rasterized, which means you cannot mix this shape with other items in the scene in 3D space (you can fake it with Layer Order and masking). Rasterized shapes also do not receive lighting effects.
To get the same kind of ribbon effect as your sample, you might have to duplicate the original bezier line twice and align a copy at the bottom and top edges of the original, and change the strokes to some other type (probably airbrush) and manipulate the blend (opacity and/or blend modes) [remember to animate the ribbon by group controls… a three line arrangement will stay aligned that way.]
Hopefully, that will get you started...