Men & Entities not visible through windows

[ManDay 0]

Ok. Keeping it short: Normally you can see Enemies and whatever through windows. Playing "Red Hotel" 2 days ago it sill was all fine. I saw the thousand of foes within the building without problems. But lately I cannot see the ppl who are behind the windows. I already had this problem with OFP-LAN-MP sometimes - thought this was default behaviour - but since in ArmA I always was able to see through windows etc it now is really annoying it all changed without a reason.

no new drivers - no other settings as far as i can tell.

I stated the same in the german counterpart of this forum where many ppl were extremly astounded I dont feel comfortable with that issue - cos .... they thought this was something normal. They obviously were playing with that kind of bug for ages now without even knowing that it is a bug

ok guys. what is that all about?

[ManDay 0]

lol. 51 hits and not one awnser

So what? Did you not understand my problem? Or is it something else?

[dm 9]

Its an issue caused by the texture formats used.

Its to do with the alpha (transparency) sorting, if the soldiers alpha is a lower priority than the window, he will become invisible when behind it. Similar issues can be observed with the muzzle flashes, and many other transparent objects.

[ManDay 0]

Yes mate. But the thing is: It worked all fine for month. days ago (48 hours to be precise) I was still able to see through the SAME wins in the SAME missions

btw: what kind of bug is that? why is arma the only game in the world where alpha-channels do not work properly? I mean if ArmA was some kind of antiquated freeware i will understand. but I paid my 50 euros (or more?) for that current game. and this is not "just a bug" if it is what you say. that is essential.

^ this is rethorical "btw" and not supposed to be answered

[Average Joe 0]

Same Applys for invisible buildings through vehcile windows, would be nice if this was sorted

[5133p39 12]

Can you give exact example when this is happening?

I haven't noticed this issue in ArmA (which doesn't mean it doesn't happen), except when i run it in windowed mode.

[Balschoiw 0]

Simply play the single player mission where you have to clear a town. At the entrance of the military camp there is a watchtower with windows and a guard in there. You can´t see him when you approach the tower.

I got killed by that guy before I noticed that there actually was one up there. You can´t see him if you look at him through the windows.

[ManDay 0]

Harharharhar Guess what. I just played red hotel again... and - you will never believe - YES! I was able to look through the windows again.

It seems completly random - but at last im glad it works again

[Average Joe 0]

2 Angles,

[ManDay 0]

Im am completly confused.

I played Red_Hotel 45 Minutes agon and all the windows worked. Now I play it again - same mission, same settings, same server, same equipment - and it doesnt work no more.

[5133p39 12]

heh, i started editor, put a humwee and a soldier on the airport, and it really is happening.

I am very surprised that i didn't noticed this while playing.

[Ruckus 0]

Happens on screen windows in tents too. I snuck into a enemy camp, and crawled into a tent. I looked outside through a screen window to check for enemys. I saw none and walked outside an BAM....I was shot by 2 soldiers that were just outside the window I looked out of.

[ManDay 0]

<span style='color:red'>I got one possible reason!</span>

Start the editor and go to the hotel at grid F6. Start with defaul values for daytime, date etc.

Now:

A unit in the hotel (groundlevel) northern side will be clearly visible through the windows while the same unit at the southern side will even not be visible through open windows.

I think this is all because of the lighting-condtions.

---edit---

In that picture with the Hmmwv-test. It makes me wonder why the garage in the back is still visible while the unit itsself disappeared. Techniacally spoken: Those are both entities (aka subjects) - why does one disappear while the other is still there?

Makes one think that this behaviour is intented. But why? I dont think there is a plausible reason while ppl shall disappear behind glass

[dm 9]

In that picture with the Hmmwv-test. It makes me wonder why the garage in the back is still visible while the unit itsself disappeared. Techniacally spoken: Those are both entities (aka subjects) - why does one disappear while the other is still there?

Makes one think that this behaviour is intented. But why? I dont think there is a plausible reason while ppl shall disappear behind glass

Its because of the alpha sorting.

Do you just not believe me or something?

As for the variable conditions as to when it happens, I couldn't really clarify WHY without running some detailed tests myself. But believe me, it IS the alpha sorting causing this issue.

And it cant really be "fixed" other than tweaking the alpha order until you get minimum dissapearing issues. But even thats not guarenteed (fix one alhpa order and you'll break several others)

[wamingo 1]

It is pretty random. Sometimes you can see everything through the glass, sometimes nothing and sometimes a few things. Also happens with with buildings sometimes.

[dm 9]

Just done some quick cursory tests and can conclude this:

The issue IS caused by the alpha sorting issue, it'll be present in every game which uses the DXT formats in this manner.

The issue is tied to the time of day - since the shader used for the lighting depends on the time of day, one can assume that it has different alpha drawing priorities at each lighting stage.

Results from quick tests at the hotel at F6:

Daytime: I can see out, but can not see in through MOST windows. There are a few windows which I cant see out of, but can see in through.

Dawn/Dusk/Night: All have the same results - I can see IN but not out. This suggests different alpha sorting priorities.

As a note: those windows which appear "open" (have half a blind, or the crooked blind) are still alpha textured surfaces. Thus will still cause the problem

[ManDay 0]

Can you tell what exactly "alpha sorting" means? I do programming and 3D-Grafics myself but I never programmed any DirectX/OGL so I don't know what this means.

And why are other programs capable to display alpha-textures properly and arma is not?

[dm 9]

Alpha sorting, a very basic, and somewhat abstract description:

All textures in ArmA are now of the *.paa format, which is RGBA and uses DXT compression. ( See the Wiki for more technical info)

Every surface [in a 3d model] which has an alpha enabled texture (i.e. all of them in ArmA) has an "order" at to what priority the alpha channel (i.e. the transparency) is given at render time.

If the alpha priorities are sorted correctly, you will see everything rendered correctly, if they arent sorted correrctly you get this dissapearing issue as seen in ArmA.

And other prgrams which use the same texture formats DO suffer from the same issues. Its not specific to ArmA/OFP

[highplainsdrifter 0]

@Deadmeat- Thank you for the informative posts! Would lowering the detail levels help resolve the issue, i.e., would setting the texture, objects, shadows, post-processing etc... to "low" or "very low" result in proper alpha rendering? Or is there any particular setting that would affect the priority level of the alpha drawing more than the others? Basically I'm thinking (hoping?) that giving the engine fewer textures to draw would result in fewer textures disappearing.

@Manday - this may be completely beside the point, but last night I noticed that the changes I made in Nvidia control panel had mysteriously reset themselves. Previously, I had set AA and AF to "application controlled" and disabled VSync in the global settings. Last night I was having problems with graphics. When I brought up the control panel, the global settings were set to AA-4x, AF-2x, and Vsync was on. After fixing them, my graphics problems disappeared.

I don't know if it has anything to do with this issue, but it's just something to check on when you're getting inconsistent results with the same map. (I suspect that, in my rig, the random reset problem results from the nvidia control panel and rivatuner not cooperating in the management of my 7900GT.)

[dm 9]

@Deadmeat- Thank you for the informative posts! Would lowering the detail levels help resolve the issue, i.e., would setting the texture, objects, shadows, post-processing etc... to "low" or "very low" result in proper alpha rendering? Or is there any particular setting that would affect the priority level of the alpha drawing more than the others? Basically I'm thinking (hoping?) that giving the engine fewer textures to draw would result in fewer textures disappearing.

Unfortunately not (at least not from any technical stand point)

The Alpha sorting is stored in the p3d (model) its self, so altering the graphics settings wont really make much difference. (Unless you get lucky and the next lod down has a different alpha sort, but its unlikely to help.

[MAA3057 0]

This has been around since OFP1.

[mr reality 0]

This has been around since OFP1.

All the more reason for it to not be in ArmA   .

[Metal Heart 0]

What (I think) DeadMeat is saying is that (if you use z-buffering,) transparent surfaces need to be rendered last, and in order from back to front because every pixel has a z-value (distance from observer) and the pixel of a new surface being rendered will only be set if its z-value is closer than the one already there from previous surfaces.

As to why would the rendering order be enforced by the models I have no idea. Maybe perfromance.

[rundll.exe 12]

I dont get it, why should you add a priority to the texture on the model itself???

This makes it impossible to work correctly EVER

the window - hmmwv - soldier example is perfect:

you can look trough the window, trough the HMMVW to the soldier but also trough the hmmvw, trough the window to the soldier.

Those examples cant work with the same priorities if I understand it right.

So what moron thought of this system? while the solution in theory sounds simple: let the engine apply the priorities depenent on the distance from the camera...

I might not understand how it works, but it just sounds akward...

[ManDay 0]

Indeed. I dont understand the issue either. What is the problem with Z-Buffering Technology? It always worked fine so what is that alpha-priority there for