Question for Steve about window glass

[RogerA 3]

Thanks for the Fixer Steve. I was using Dx10 even before the Fixer and with it the vast majority of issues have been fixed.

 

I have one Dx10 native aircraft, a freeware Grumman Duck (from the SimOuthouse) where the canopy glass is invisible in Dx10. No amount of fiddling with the glass texture alphas or images works. Have you any ideas from the Fixer tools that might help?

 

Kind regards,

 

Roger.

 

 

[SteveFx 258]

Can you send me a link to the download as a pm I will look after Easter, nothing obviously springs to mind.

[RogerA 3]

Thanks Steve,

 

I'll pm you a link.

[SteveFx 258]

Thanks Steve,

 

I'll pm you a link.

You can fix it by going into debug and disabling DX9 Style Alpha Func in the 2nd column. That may mean that a very few sceneries don't work - but the only one I can actually recall is an Irish freeware airport.

 

I need to look into it a bit more to figure out why this option causes this issue with this plane!

[RogerA 3]

Many thanks Steve. I'll give it a try this evening.

[RogerA 3]

Works a charm!

 

Cheers,

 

Roger.

[SteveFx 258]

The problem is actually that the FSX SDK allows for various alpha testing options which are rarely if ever used.

 

The DX10 implementation only supports one alpha test option where pixels less than a certain alpha value are discarded.

 

This is not usually an issue because there is really only one useful option - the one DX10 implements. It is more common in DX9 to discard pixels less than or equal - which cause a few dx10 scenery oddities because of the slight difference. The debug option in the fixer corrects for this i.e it changes the DX10 test to discard if less than or equal matching the most common DX9 fsx alpha test.

 

The glass in the model uses alpha testing with the alpha testing level set to zero and the test being "always pass" i.e it enables the test but then immediately chooses an option which disables it.(This is totally pointless)

 

Because of what I think is a bug in both the DX9 and DX10 shaders the use of a Fresnel texture always sets the alpha value to zero which doesn't work well with an active alpha test.

 

Anyway in DX9 it all cancels out and ends up with no alpha testing and the glass gets drawn even though the use of the Fresnel texture sets the alpha to zero.

 

In DX10 it ends up testing the zero alpha against a limit of zero and with the fixer correction active the glass then gets discarded.

 

Anyway none of this will mean anything to anyone else but at least I will remember why this works.

[Mechanic 0]

Steve,

 

Thanks for solving this problem with my model. After testing with one of the SOH members I had suspected that it was in the Alpha Testing but was not sure until now. I do not have missing glass when running DX10 Preview so I had no problem to fix.

 

I model for FSX as a hobby (freeware only) and have picked up most of my knowledge from the experts at FSDeveloper and I can't say enough about how supportive and instructional these people are. Although I have never encountered the problem there is some sort of visibility problem with glass gauges as seen through the cockpit glass so I followed recommendations which I most probably didn't set correctly.

 

In my FSXMaterial for the glass I have the following set;

 

Z-Test Alpha

Alpha Test Level set at 0.0 (which doesn't make sense now that you mentioned it)

Alpha Test Mode: Always

Set final alpha value at render time

Final Alpha Multiply: 1.0

Z-Write Alpha

 

I'm going to eliminate this section of the material for my next release unless you can suggest a change in the settings.

 

I would like to purchase your DX10 Fixer but my next SS check is going towards purchasing Prepar3D, which I have wanted for quite a while, so it will have to wait for a couple of months.

 

Thank you

 

Paul "Mechanic" Domingue

 

[SteveFx 258]

hello Paul

 

"Always" means always pass the test (i.e never discard) which is slightly confusing in my opinion and (in DX9) effectively disables the alpha test

 

I would just set Z test Alpha off and it will be fine in DX9, DX10 and DX10 with the fixer.

 

A Fresnel texture always resets the alpha value to zero so I dont see a use for alpha testing when one is present.

 

Steve