Models being seeable through smoke

[engen 0]

Dunno if this has been brought up before, did a search but it didn't give me anything.

Anyway, the problem is that i've got a vehicle which can be seen through smoke. When it fires, the smoke from the cannon comes from "behind" the vehicle. The same happens with the dust it creates when moving. This is a bug i've seen on many other addons aswell.

It's sorta pointless if you discharge your smokelaunchers and people will still be able to see your vehicle.

Anyone know a way around this?

(I noticed on my lower resolution lods, the problem doesn't exist btw.)

Cheers,

Shar.

[orson 0]

I believe its to do with the View Geometry or lack of one.

Use the same model as your shadow LOD and if i recall , you need to make it convex

Structure / Convexity / Convex Hull

Hope that helps

[engen 0]

Still doesn't seem to help. I've tried with a view geo, without, (as some BIS models don't have these?) and with another p3d's view geo.

The vehicle can still be seen through smoke. And by that, I mean that the player can see it through the smoke, not the AI.

Thanks tho.

[Guest RKSL-Rock]

I seem to remeber this being about Alpha layers or something...

In oxygen select your model and in the "Faces" menu use either "Move to Next Alpha Channel" or "Move to Previous Alpha Channel". I think if you move it to the lowest channel it might sort out your problem...

[colonel_klink 0]

edit Ok I have a similar problem and even doing this in the view lod by removing all the parts that have alpha textures didn't help.

[orson 0]

Arrr , it must be to do with selections in your LOD's or grouping of components .

Maybe

[raedor 8]

i had the same problem. i hate ofp!

[orson 0]

I wonder...do you use .paa textures ?

Try .pac

again just guessing here as i only had the problem briefly and i cant remember which one thing i did that fixed it , but all my exterior textures are .pac .

[dm 9]

It is definitely NOT a paa Vs. pac issue, I have just done some tests, and the model is still visible through the droped particles regardless of the texture format.

I'm inclined to think that its a poly-count or geometry issue more than anything else. I will do some more tests and see what I come up with.

[DanAK47 1]

Edit: I guess you already tried this, but it worked for me. I created a 1.000 LOD and now everything is fine (even when the game uses the 0 LOD).

http://www.flashpoint1985.com/cgi-bin....t+smoke

I was having the same problem. I knew I had seen something about it before on the forums. I searched and found that thread, did what he said, and fixed it.

If you are too lazy to read it, try creating another less detailed LOD.

I also added a view geometry LOD (which has nothing in it at this time) beforehand, so you might have to do both...

[dm 9]

I've been testing with models that have extensive LODs, as well as all the associated geometries, and it still isnt going away. I've tested polycount, and it has nothing to do with that (models that dont occlude behind smoke as they should still dont occlude properly when the polycount is reduced dramatically - from ~4000 to ~2000)

More tests going on as you read.

[colonel_klink 0]

Hmm seems this has been around for a while.

I just tried renaming my 0 Lod to 1, zip.

Just wondered if it is something to do not with polycount as such, but the number of objects.. just a thought.

[Jezz 0]

a friend had this same problem when he origanlly created a bmd 1 but hadnt made any other lods other than the first 1.0 lod and the other ones required to get it in to game ie geo, landcontact, memory, fire geo, and view geo. and when he loaded it up in ofp to see how it looked in ofp he found that you would see the apc through but when he created the other detail lods the problem disappeared.

if you want ill try and recreate the problem tonight by remove all the lods except for the first one and see if the problem will come back

[Guest RKSL-Rock]

Well I have this with an aircraft im making, but its only with the Afterburner animation.

The model is 5500 polys and as soon as I use the afterburner the model is obscured by smoke but not the vrtule animation.

So logically and as far as I know its down to the game engine's ways of dealing with the Alpha channels....as I said before.

It would be odd that the rest of the model isnt affected if it was a resolution issue.

[colonel_klink 0]

I have found that close up the helo (current model) can be seen with the smoke effects behind. Move away and the smoke then covers the model. Tried this with 3rd person camera. I think you are right it must be the way the engine handles alphas, but doesnt affect every model. Strange indeed.

[engen 0]

Some (strange?) progress:

Yesterday I made a brand new geolod. Seems now, the vehicle discharged smokelaunchers conceal the vehicle properly as they should (they didn't before).

Now for the weird part - The dust and cannon smoke is STILL not working.

[dm 9]

I think you are right it must be the way the engine handles alphas, but doesnt affect every model. Strange indeed.

The strange thing is, I tried exactly the same model (BAS MH-60L) which has paa textures as standard, I converted every testure to pac, re-binarised and still the problem occurs.

I have a feeling its less to do with the alphas themselves, and more to do with the face order.

I'm going to test the face order today and see what I come up with.

[DanAK47 1]

Maybe the order that the LODs are created has something to do with it.

[orson 0]

Well if 2 of us thought of the same thing..there might be something in it  

This is my order and its based upon the MMP Marder and BIS M2A2

http://www.project-ukf.com/Orson/images/myLODs.jpg

But i somehow think that they get sorted automatically

[orson 0]

Some (strange?) progress:

Yesterday I made a brand new geolod. Seems now, the vehicle discharged smokelaunchers conceal the vehicle properly as they should (they didn't before).

Now for the weird part - The dust and cannon smoke is STILL not working.  

Dust and smoke being created by the memory lod , try cuting and pasting into a new memory lod see if that works ?

[suma 8]

I think you are right it must be the way the engine handles alphas, but doesnt affect every model. Strange indeed.

The strange thing is, I tried exactly the same model (BAS MH-60L) which has paa textures as standard, I converted every testure to pac, re-binarised and still the problem occurs.

I have a feeling its less to do with the alphas themselves, and more to do with the face order.

The problem you are seeing is quite intricate. I will try to describe what I think is happening there, and hopefully you will find some way to get around it:

1) Objects in OFP are rendered in two groups. 1st are rendered all objects which are considered opaque, followed by all alpha-transparent objects, which are sorted by z (distance from camera).

2) Dust and clouds are rendered together with the 2nd group, but no z-writes are performed during their rendering.

This means that if any object is rendered in the 2nd group, it can create artifacts like you describe, because there is no simple correct z-ordering of the objects. You cannot tell if the dust should be rendered before or after the object by looking on the z coordinate only. Any way you decide, nasty artifacts may arise depending on what is behind what. If you draw dust first, the object in questions will overwrite it later because the dust did not change z buffer content.

Object is considered alpha-transparent (and rendered in the 2nd group) when it has some .paa textures with alpha channel AND when its average alpha (calculated across whole model surface, pac textures included) is below certain limit.

To avoid the artifact you can do either of the following:

- ( A ) avoid large transparent areas in your textures to keep the average alpha close to 1 (this applies to both pac and paa textures)

or

- ( B ) avoid textures with continuous alpha channel completely. If you will use only discreet alpha textures (pac) in your model, it should be rendered in the 1st group

or

- ( C ) keep the object radius small to make z-ordering easier

Note 1: I suppose it will be easier to meet the step (A), as avoiding alpha-blended textures as required in (B) completely is often not possible. You will probably need them for glass or rotating blades. As for ©, there is often little you can do reagrding the model size, but you should at least take care not to place any unnecessary points far from the model center in any of the LODs, including memory.

Note 2: Some original OFP models exhibit this problem as well. I think most choppers do, from static objects most notable example is church ruins on Kolgujev.

[dm 9]

Thanks for the input Suma, I will do some more tests with this in mind, and see what happens.

[engen 0]

Thanks everybody for your help, i've sort of solved the problem atm, and the thing that helped me was:

Quote[/b] ]- ( C ) keep the object radius small to make z-ordering easier

Had mempoints far from the model, for an autocannon recoil. The "bug" still seems to be there however, if you are close to the vehicle.

Also, those mempoints made the vehicle rotate on the spot when it stopped moving, and it did so until you told it to move somewhere else.  

Again, many thanks.

[Master_Chief 0]

lol! No wonder I could never fix this problem on my water addon. Dust and tranparent textures always messed it up. Turns out that my addon breaks all these rules as it only uses transparent paa textures and it is huge!