We're using quite a few custom gauges in BP.
+Custom:
Position: (1261, 250)
Name: BPTaccom
Text: TacNet Uplink
X Offset: 3
Y Offset: 2
Gauge Type: WINGMEN_STATUS
Slew: NO
Active by default: NO
Filename: directives1
+Custom:
Position: (1261, 262)
Name: BPTaccomA
Text: System in client mode
X Offset: 5
Gauge Type: WINGMEN_STATUS
Slew: NO
Active by default: NO
Filename: directives2
+Custom:
Position: (1261, 271)
Name: BPTaccomB
Text: No valid uplink targets
X Offset: 5
Gauge Type: WINGMEN_STATUS
Slew: NO
Active by default: NO
Filename: directives2
+Custom:
Position: (1261, 280)
Name: BPTaccomC
Text:
X Offset: 5
Gauge Type: WINGMEN_STATUS
Slew: NO
Active by default: NO
Filename: directives2
+Custom:
Position: (1261, 289)
Name: BPTaccomD
Text:
Gauge Type: WINGMEN_STATUS
Slew: NO
Active by default: NO
Filename: directives3
The important bits to remember are:
-Custom Gauges need to be defined for every resolution separately. The bits quoted above are from the standard 1440x900 layout we're using as a base.
-The "Name" field defines the name you need to use as an argument for the hud-set-* sexps.
-Text can be left empty
-"Gauge Type": This is a bit complicated. Every hud gauge needs to have a gauge type. Which one you choose is pretty much up to you; the important part is that you can deactivate/activate all gauges using the "activate-gauge-type" sexp.
-"Slew": If set to yes, the gauge will react to ship movements.
-"Active by default:" If set to No, the hud-gauge-set-active sexp needs to be used in order to display the gauge.
Now, for your specific temperature gauge, the tbl entry would look like this:
+Custom:
Position: (x, y)
Name: Temperature
Text: Bla
X Offset: 5
Y Offset: 3
Gauge Type: RADAR
Slew: NO
Active by default: NO
Filename: objective1
Where (x, y) needs to replaced with valid coordinates. In-game, you can use hud-set-message to display a variable value.