Alpha test -> alpha to coverage tool

[WKjun]

Hello again!

Thanks for your instant reply. I'm now at work and I'm going to test your suggestion in a few hours. I did not know about the possible values for "ForcePixelFormat". I only tried "0" (default) and "1", not knowing about it's meaning. Has this something to do with color depth? So assuming "15" or "16" doesn't work, are there other settings, like "24" or "32", I might try?

 

[WKjun]

By the way, what is your recommendation about forcing settings by driver or app? At the moment I set both to the same setting (2xAA, 16xAF, VSync on, etc). Is it better to set the driver to "let application decide" and setup the app/opengl32.ini only?

 

[WKjun]

Hi there,

at least it works with ForcePixelFormat 15 or 16 (I spotted no difference). But if I come closer to a plant for example it is not smooth opaque but more or less opaque pixels can be seen, the effect is pretty awful in low and mid resolutions.

I cannot post a screenshot because only pics from a websource is allowed, no uploading.

I've noticed in your beautiful demo for Alpha to Coverage that there is a mode called Alpha Blend. It seems that this mode can solve this issue. Can it be activated?

 

[Humus]

The pixel format is just an index into the driver's list of supported pixel format. You can find what pixel formats your driver supports by using a tool like GLView. Select a double buffered, multisampled format with the desired number of samples, with no accumulation buffer.

Alpha blend looks nice, but can't be forced through a tool since it requires application side sorting, unlike alpha test that it's overriding.

 

[WKjun]

Hi, I'd like to upload a screenshot here, but I do not have any web recource to put it on. Is there any way to upload to the forum directly?

However, it may be because of the game Soldier of Fortune 2 (not in the list of tested games). I try Doom 3 next.
At least I've found out (GLView) which values lead to the black background and which don't. This problem is solved. But even with the correct index value set in the INI you recommended, there is no noticable difference in transparency quality.
In SoF2 palms get their transparency through "pixel perforation", they are not really transparent. Only by raising the resolution to >1600x1200 these pixels get smaller and so it looks more like smooth transparency.
On the other hand grass and bushes look fine!

I would like to show you this, but how? (E-Mail?)

 

[Humus]

Try setting ForceMipMapping = 1.

 

[Bludd]

Hi, I'd like to upload a screenshot here, but I do not have any web recource to put it on. Is there any way to upload to the forum directly?

You can use http://imageshack.us to upload images.
Copy the generated BB code for thumbnails after uploading and paste into a post here. It should work a treat.

 

[WKjun]

GLView:


OpenGL32.INI used:


SoF 2 (w/o alpha to coverage):


SoF 2 (alpha to coverage):


The palm is dark green actually. Quiet dark. I've tried ForceMSAAMode=0/2 and ForceMipMapping=0/1.

 

[Humus]

Well, that looks like the alpha channel doesn't encode transparency per se but was only made to work with their particular alpha test. In that case there's not much you can do. Maybe boosting alpha channel contrast could help.

 

[WKjun]

Thanks for your analysis. How may I manage boosting alpha channel contrast only?

 

[Humus]

I could throw in a global option in GLoverride. Should be a quick fix, but it may change the look of other stuff like translucent surfaces as well.

Edit: Done. Download the latest version and try. It won't work with precompressed textures, but all other forms of textures should work. There are two new parameters, AlphaScale and AlphaBias. Try tweaking these and see if it improves any. Judging the screenshots perhaps AlphaBias = 0.4 or something like that could fix it.

 

[WKjun]

That's it! Thank you very much! Sorry for my late reply, I had so much work to do. Now even this game is fun to play!