Need a correct window shader for custom texture

diego · Post by **diego** » Sat Apr 30, 2005 7:01 am

I've seen some other posts on windows, but I didn't see anything regarding this particular shader issue.

I made a custom window texture and tried a couple of window frame shaders from Mohaa to make it work. The env map is working fine on the glass. And the window frame is opaque. But I have a lot of shades of gray in the Alpha channel on the glass that are not showing up. Instead it looks as if my Alpha was only black and white.

The image on the left is what I get with the Alpha channel on the right:

http://webpages.charter.net/dt3d/screen ... indows.jpg

Here are 2 almost identical shaders that I tried but neither uses the alpha channel correctly:

Code: Select all

textures/Praetoria/windows/window_transparent_01
{
	qer_editorimage textures/Praetoria/windows/window_transparent_01.tga
	qer_keyword praetoria
	qer_keyword window
	qer_keyword glass
	qer_trans .4
	surfaceparm glass
	{
		map textures/Praetoria/env/env_bright.tga
		tcgen environment
		alphagen const .2
		blendFunc blend
	}
	{
		map textures/Praetoria/windows/window_transparent_01.tga
		depthWrite
		alphaFunc GE128
	nextbundle
		map $lightmap
	}
}


textures/Praetoria/windows/window_transparent_01
{
	surfaceparm glass
	qer_keyword broken
	qer_keyword window
	qer_keyword glass
//	cull none
	qer_editorimage textures/Praetoria/windows/window_transparent_01.tga
	{
		map textures/Praetoria/env/env_bright.tga
		tcgen environment
		alphagen const .2
		blendFunc blend
	}
	{
		map textures/Praetoria/windows/window_transparent_01.tga
//		blendFunc blend
		depthWrite
		alphaFunc GE128
	nextbundle
		map $lightmap
	}
}

Post by **jv_map** » Sat Apr 30, 2005 7:20 am

Get that alphaFunc GE128 outta there

And use blendfunc blend on the window stage.

diego · Post by **diego** » Sat Apr 30, 2005 7:27 am

LOL

It just occured to me to check the scripting forums. Silly me. I'm now using Tom's blue glass shader from his door2 tutorial. It works fine. A bit opaque, I'll tweak it a bit.

diego · Post by **diego** » Sat Apr 30, 2005 9:30 am

Hmm, i have another problem with this window.

The window brush is textured on all sides with nodraw except for the front face. The transparency is working. But if I move into a position where I can see 1 window through another window, the window in the back draws on top of the window in the front. Also, the glass surface parameter does not work.

If I put the window texture on both sides of the brush, the glass surface parameter works, and the draw order seems correct between 2 windows. But I can see both sides of one window at the same time -- ie, the texture is drawn twice.

Post by **jv_map** » Sat Apr 30, 2005 12:18 pm

Hmmm maybe get rid of the 'cull none'

diego · Post by **diego** » Sat Apr 30, 2005 8:49 pm

Dropped the Cull none. The window has nodraw on all surfaces except the outside surface. The inside doesn't draw at all. Surface parameter doesn't work. And the rear windows draw on top black.

http://webpages.charter.net/dt3d/screen ... ndows2.jpg

Here's the shader. I'm not very knowlegable about shaders. I've mostly gotten by with cut-and-paste shaders based on tuts and and stock stuff.

Code: Select all

textures/Praetoria/windows/window_transparent_01
{ 
	qer_editorimage textures/Praetoria/windows/window_transparent_01.tga
   qer_keyword window 
   qer_keyword glass 
   qer_trans .45 
   surfaceparm glass 
//   cull none 
   { 
	  map textures/Praetoria/env/env_bright.tga
      tcgen environment 
      alphagen const .4 
      blendFunc blend 
   } 
   { 
      map textures/Praetoria/windows/window_transparent_01.tga 
      blendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA 
   } 
   { 
      map $lightmap 
      rgbGen Identity 
      blendFunc GL_DST_COLOR GL_ZERO 
   } 
}

tltrude · Post by **tltrude** » Sun May 01, 2005 3:54 am

If you remove "cull none" it defaults to "cull front". At least that is what the shader bible says. Every surface has two sides and if the front is culled, the back surface of the face is all you see. That is why most textures look reversed when you apply them (no cull none in the shader).

The normal windows in the game all have the same problem as your screenshot. I can't remember what fixes it, but you can check my test pointer map for a new window shader that seems to work.

Click on my sig logo to find it.

diego · Post by **diego** » Sun May 01, 2005 5:05 am

One difference I can see is those windows are perfectly clear. It also looks like you are using 2 images with different alpha channels.

What is the .FCM file in your pk3 that is associated with those windows? That's the second time I've seen that for glass, but I can't open that file.

Post by **jv_map** » Sun May 01, 2005 5:50 am

Adding a depthWrite in the 2nd stage should fix it... but you may get transparency problems... (maybe use alphafunc again).

diego · Post by **diego** » Sun May 01, 2005 9:41 am

I can't get any of these shaders to work correctly. I've been going thru the shader manual all day and experimenting with different settings in addition to trying shaders from your tutorials.

The closest I got had all the reflective and transparency effects working, but window frames for windows behind the one I was looking through would draw on top of the reflective glass layer.

Typically, If I use a "blendFunc blend" on the second stage, 1 of 2 things will happen:

The second layer of windows will not draw at all
or the second layer will flicker off and on depending on the camera orientation.

I noticed that even if I disable the 2nd stage completely, and just render the reflective env layer in the first stage, you can see the windows in back pop on and off -- the alpha constant setting has to be pretty opaque to notice it.

I'm more than willing to give up the soft blending for the window frame as long as I can keep the reflective layer drawing in the correct order. Here is my current shader:

Code: Select all


textures/Praetoria/windows/window_transparent_01
{
	qer_editorimage textures/Praetoria/windows/window_transparent_01.tga
	qer_keyword glass
	qer_keyword window
	surfaceparm glass
	{
		map textures/Praetoria/env/env_bright.tga
		tcGen environment
		alphagen const .5
		blendFunc blend
	}
	{
		map textures/Praetoria/windows/window_transparent_01.tga
		depthWrite
		alphaFunc GE128
//		blendFunc blend
	nextbundle
		map $lightmap
	}
}

Here is an image showing with the 2 most successful variations:

http://webpages.charter.net/dt3d/screen ... ndows3.jpg

tltrude · Post by **tltrude** » Sun May 01, 2005 11:19 pm

Maybe it is the lightmap. Have you tried doing a -final light compile?

diego · Post by **diego** » Mon May 02, 2005 3:57 am

No, I'll give that a shot tonight. It shouldn't take long. I'm only working on 1 building at a time.

---------

Just finished. No difference. So, what are all those .FCM files for?

Post by **jv_map** » Mon May 02, 2005 6:56 am

.fcm I think is a fence mask... presumably helps the game in determining which portions of the windows are solid / wood and which are non-solid / glass.

Post by **Rookie One.pl** » Mon May 02, 2005 7:13 am

Really? Haven't ever noticed a difference in shooting a wooden part of a window, it all sounded glass...

From what I can see the depth test for the windows is enabled only kind of partially. Try adding a depthFunc lequal to the first stage. Just mess with depthFunc and depthWrite, add them in random combinations in random places.

diego · Post by **diego** » Mon May 02, 2005 9:29 pm

Well, that's what I have been doing. I've gone through two versions of the shader manual trying to find a combination of settings that works.

If I keep the GE128 on the 2nd stage, the window frame at least draws in the correct order and the 2nd layer of window frames doesn't pop on and off. But the window frames always draws on top of the first stage of reflection. If I turn down the alpha const on the reflection texture, this is not as noticable, but it's still wrong.

One thing I noticed in Tom's broken window shader, he is actually using 2 textures to make that work. One texture has the broken glass in it and he is blending it with the reflection map. The second texture used in the second stage has just the frame in the alpha channel and that has the GE128 blending.

I didn't want to make a 3rd texture but I'll give it a shot.

Regardign FCM files. I saw something online about it being a "Forward Compression Map". But that might not necessarily be the correct filetype for q3 games. I downloaded a tool that is supposed to compress and uncompress FCM files, but I couldn't get it to work.