Transparant fence

#1
hi,

I have a problem (again :banghead: ) I made a fence in gmax made a double sided material and used a mask, to make parts transparant. Everything was alright I thought. I came back from a flight and was taxiing to my new scenery and I saw the fence, that was alright, but the building behind the fence was partly invisible too :confused: the fence and building are gmaxed seperate and have seperate bgl files. Any ideas?

 

arno

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#2
Yes, sounds like the famous drawing order problem.

FS determines which object is further away using the RefPoint coordinates and the object that is further away will be drawn first. When another object is then drawn in front it determines that parts of the object behind can be skipped as they are hidden. Of course this goes wrong for transparant objects.

One option to solve this is controlling the drawing order completely manual, but that is very complex and would require a lot of source tweaking (not recommened thus).

Probably easier for your fence is to do something with the texture. What kind of format did you save it in? It seems that DXT1 textures are used different by the scenery engine and that they solve the drawing order problem.
Another option might be to make the material a bit transparant in GMax as well (in the material editor), it seems that also has an influence on how FS shows it.
 
#3
Ok thank you

The problem is solved, I saved the images as an DXT1 (previous it was saved as DXT3) Everything is alright now. Although DXT3 was something better, the quality is high enough.
Thanks

Jorrit
 

arno

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#4
In general DXT3 is only needed if you want more then a 1 bit alpha channel, for the rest the resulting image is the same as DXT1. So only when you want to use different levels of transparancy you need DXT3, all other textures should be DXT1.
 
#5
I knew that, but in a tutorial I've read they said that you could better make more levels, when creating a fence, because it would be more realistic. And that was true, with only one level you will see either everything or nothing, If you look with some angles to the fence, you wont see anything with just one level of transparentie, if you look to a fence with more levels of transparentie it looks better. But if I need to choose between a good fence and transparant buildings, or a less detailed fences and normal buildings, I choose the last one ;)
 
#6
Another problem with the fence. It is not really a problem, but the shadow isfrom the plane where the fence is made of. I think it is better without a shadow, because the fence is for 80% or something transparent and now I have one dark shadow, which doesn't match reality at all. Don't know if it is possible and easy enough for me to remove or edit the shadow.., but maybe you now a simple solution.
 

arno

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#7
Have a look at [thread=175]this[/thread], the same problem is discussed there. The best option is probably to set the opacity to 99%.
 

rhumbaflappy

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#8
Hi all.

A word about alpha channels.

I had a discussion with Holger Sandmann about singular alpha channels. Holger noted that imagetool will identify some alpha channels as Alpha, rather than as colorkey. What we found is that the singular alpha channel need not be black and white, but can be a greyscale of 256... something I had not read of before.

http://forums.avsim.net/dcboard.php?az=show_topic&forum=123&topic_id=21419&mode=full

Dick
 
#9
Hi all, Happy new year.

I just joined so this is my first post.

I am intrigued with these transparent textures. I need to reduce a model's poly count drasticaly. It is a grain terminal and each hopper has a dozen legs with bracing. By using boxes it is not possible to export the model due to its complexity. So I would like to replace the legs with a transparent cylinder and add a bit map of legs to the inside and outside. Your fence looks good but I have no idea how to do this. I did make a texture and it had transparent areas, but when it was applied to the cylinder the transparent areas were no longer transparent.

I'd really appreciate a little tutorial on how to do this.

Thanks heaps for any help provided.
 

Firestriker

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#10
Happy New Year All,

I recently got a bug to build a scene from sometime ago. Part of the scene has a helipad on the roof of a building. I used transparent textures quite extensively for both fencing and the structural legs of the pad and the gangway around the pad. The textures were DXT1 with simple black and white alphas. The material was set for double sided and lots of tiling was done with the mapping on each poly. So, Manfred, I think transparant textures would be a good way for you to go to reduce your poly count. If you already have a complex mesh built for your cylo, try using them as a basis for developing your textures using simple screen shots. Then apply the textures to simpler meshs.

It was mentioned about using transparancy in the material setting. On another part of the scene there is a canopy with a metal frame and translucent panels for the roof and side, just a single object. All went well in gMax, however, once I compiled the scene to see how it looked, the translucent panels became detached from the object and transported several feet away from the frame. I tried detaching them from the frame, no difference. Tried linking the panels back to the frame, no difference. They both have the same pivot point. Then I set the material transparancy back to 100% from 50% and the panels were no longer detached. So I guess I will have to use a texture with some transparancy instead of relying on the material alone. Oh well!!!

Lou
 

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#11
Hi Lou,

That looks great :) I don't suppose you would be interested in writing a small step by step tutorial on how you made that fence? I would really apreciate it.

Manfred
 
#13
arno said:
In general DXT3 is only needed if you want more then a 1 bit alpha channel, for the rest the resulting image is the same as DXT1. So only when you want to use different levels of transparancy you need DXT3, all other textures should be DXT1.
S! Arno,

I too am having a problem with transparencies. I have built a hangar that is hollow and has textures on inside as well as outside. I prefer to have Partial Transparencies for the windows therefore used DXT3 when saving. This does a fine job of making the windows transparent BUT of course I do not see my inner textures but only the horizon away off in the distance. I tried saving as DXT1 but that seemed to remove the transaprency, I guess that is because it was not Fully transparent and only Partial.............

Am I right in assuming that I must make the windows FULLY TRANSPARENT and save as a DXT1 to enable me to see the inner textures?

Thanks again for the great forum

Al Gay
Flight Ontario
 

arno

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#14
Hi Al,

If you are able to control the drawing order in a different way, then you can also use DXT3 textures. It is just that with DXT1 FS will automatically correct the drawing order.

Are you using the same texture for the in and the outside of your hangar?
 
#15
Arno,

Using the same texture for inner and outer, well yes and no. I tried to open a finished texture, DXT1, in PSP, darken it and then save a copy as a _lm for a night texture. That does not seem to work, it loses its alpha channel. I have found that I can though make a copy with Imagetool and retain the alpha channel. BUT I cannot darken a specific area in Imagaetool so am having a problem with a night texture. It looks like I may have to remake the night texture completely, darken it in PSP and then do the transparency work and then save as a DXT1.

They sure don't make things easy. :confused:

Al Gay
Flight Ontario
 

arno

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#16
Hi Al,

I was asking about the texture name as recently someone found at that the parts are ordered according to there texture name. So that gives you a way to control the drawing order. So if the name of the inside texture would be before the one of the outside texture in the alphabet, your problem should be solved.

About the night texture. Did you open it in PSP in a format that supports the alpha channel (TGA for example), in that case you should not lose it.
 
#17
FireStriker (listen in Arno and Brien) I ran into exactly the same thing while trying to make a transparent obs light globe. Another user and I hacked on this one for days and came to the conclusion that it's a malady of the makeMDL.exe. We found that it was associated with the proximity of an Fx attach point.. we think .... 100% reproducible but 0% explainable. We posted in several forums and no one even commented except Arno came to the same basic conclusion we had.
 

arno

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#19
JeffS said:
Can someone enlighten me as to what a DXT5 is ???
That format is not supported by FS, so you can forget about it.
 
#20
Just a quick word on these transparent textures.

I've built a tower with semi-transparent glass, I used a 64x64 texture square the colour I like, converted to dtx1 with no alpha and no mipmaps. and set the opacity value in the material editor to 70%

The thing i've found is if I export all the tower along with the glass it does'nt work and if the glass portion of the tower is set away from the 0,0 point in gmax. I get the 'I only see the horizon through the glass and nothing else'.

If I set the glass portion so the 0,0 is in the center, and export it seperate from the rest of the building, so i would have tower.mdl and towergls,mdl. Everything works great.

Heres some pics, as you can see the other buildings are clearly visable through the glass.

Stevo
 

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