Someone was asking about this earlier today, and now that we're not busy getting XPack out the door, I finally have time to answer it.
We made some changes to the XPack code base to allow this.
And we added a flag to gauges.h: IMAGE_ERASE_ALWAYS.
Note that your gauge update rate will suffer a bit, since we erase the entire image before redrawing it again.
The gauge that we use for the 2D panel is 99% the same as the one we map into the 3D cockpit, but differs in that the 2D gauge has the new IMAGE_ERASE_ALWAYS flag applied and that its background bitmap is transparent (all black) instead of white.
<p>Well, it's about time! It's a pity that the new flag will only work with FSX + SP2 though, since the market using that is still far too small at present... :(</p>
<p>Thank you thank you thank you!</p>
<p>Am I missing something here, I don't have Xpack installed as it's screwed-up several machines in our development team? I've been producing transparent HUDs since FS2004, in both 2D and VC. In 2004 I could get the HUD information to illuminate at night. That's genuine illumination and not backlighting or using an external light source, and the remaining areas remaining transparent. I cannot get the latter to work in FSX. There are also several useful variables that won't work in FSX. FEX to me has not been the success story that others seem to think it is. Pity, FS2004 was a great version.</p>
<p>BTW, will RELOAD_PANELS ever be reinstated?</p>
<p>RELOAD_USER_AIRCRAFT takes too long, especially if I have to click around an LCD gauge to get to a particular setup. This kind of thing restores back to the starting point. At the moment, what used to take 2 seconds now takes 10 seconds, and adds a lot of time when developing/ editing a gauge. With the various updates that have appeared since FSX, I was rather hoping this variable could have come back.</p>
<p>There you go, you cannot please all the people all the time.</p>
<p>Thank you for the update on this Susan! It was the former "NO_STATIC_BLENDING" flag in previous versions (FS8 at least) and has always worked before as a "ERASE_ALWAYS" feature.</p>
<p>In fact, we used this for a long time in many gauges for some special purposes. The thing is that in FS9 this flag seemed to no longer be used, and we used it for different purposes.</p>
<p>Now, with Acell, introducing this flag back causes a failure (CTD) in one particular case: when the first element layer uses "IMAGE_HIDDEN" on a STATIC, and the second layer uses "IMAGE_ERASE_ALWAYS", then it CTDs.</p>
<p>We have also had transparent and fully VC illuminated HUDs for a long time now. What am I missing? Are we talking about transparent symbology (i.e. the actual text is partially transparent)?</p>
<p>Sigh:0, I feel your pain.</p>