Engine stage: background

Structural

Parameter	Default	Range	What it does	Group
bg_coord_mode	0	0 – 1	Which way the backdrop ramp is measured: 0 straight across the frame, 1 around a point, which turns its bands into a fan converging on that point.	post

Modal

Parameter	Default	Range	What it does	Group
bg_hue	0	0 – 1	Where the backdrop starts in the preset’s palette, as a coordinate along it.	post, main
bg_bright	0	0 – 1	How lit the backdrop is; 0 is black and the scene draws on nothing.	light, main
bg_vignette	0	0 – 1	Darkens the backdrop toward the corners, pulling the eye to the middle.	post
bg_angle	0	0 – 6.2831855	Direction the backdrop ramp runs in, in radians; 0 runs bottom to top.	post
bg_hue_span	0	-0.5 – 0.5	How far along the palette the ramp travels from bg_hue; 0 is a flat colour.	post
bg_center_x	0	-2 – 2	Horizontal point the angular ramp’s bands converge on; 0 is the frame’s middle and 1 its right edge. Does nothing while bg_coord_mode is 0.	post
bg_center_y	0	-2 – 2	Vertical point the angular ramp’s bands converge on; 0 is the frame’s middle and -1 its bottom edge. Does nothing while bg_coord_mode is 0.	post
bg_shade	0.72	0 – 1	Brightness multiplier at the ramp’s start, so a sky can be dark at one edge.	post
bg_shade_end	1	0 – 1	Brightness multiplier at the ramp’s far end.	post
bg_ramp_gamma	1	0.25 – 4	Bends the ramp’s progress: below 1 the far colour arrives early, above 1 it holds off.	post
bg_band_amount	0	0 – 1	Strength of a second colour band laid across the ramp; 0 removes it.	post
bg_band_angle	0	0 – 6.2831855	Direction the band runs in, independently of the ramp, in radians.	post
bg_band_pos	0.5	0 – 1	Where across the frame the band sits.	post
bg_band_width	0.15	0.02 – 1	How wide the band is; narrow reads as a horizon, wide as a wash.	post
bg_band_curve	0	-1 – 1	Bows the band into an arc instead of a straight line.	post
bg_band_hue	0	0 – 1	Where the band’s own colour is picked from the palette.	post
bg_band_hue_span	0	-0.5 – 0.5	How far the band’s colour travels along the palette across its width.	post