Alpha priorites

[Quetzlsacatanango]

I am making a cyborg follower for Old World Blues, basically a machine body for your disembodied leftovers. I have it almost where I want it, except for one little thing:

 

http://www.newvegasnexus.com/imageshare/images/1316332-1323883268.jpg

 

I finally got the tri-radii oscillator to go around the heart while preserving its animation. Problem is there is a transparent "plasteel" (aka vault security helmet visor) in front of it for protection, but the oscillator doesn't show through it.

I know there is an issue with nif not layering alpha quite as well as you would like, but I also remember reading something about being able to set the priority for different alpha properties (something to that effect). Does anyone know what I'm talking about? I would really like for it to show the oscillator first, then the visor, if that is possible.

Thanks

[Jeoshua]

As far as I understand the NIF format, there is no way to specify this kind of behavior. Alpha channels do not layer at all, and if you have two different transparent meshes then the game engine will display the one closest to the camera and ignore the one behind it. This happens with water, glass, and basically everything else in the game.

 

There is one way known around this issue, and it is used in the Fallout 3 game already. But I'm telling you right now, you're not going to like it:

 

1-bit alpha does not have this problem at all.

Edited December 17, 2011 by Jeoshua

[Ghogiel]

Objects are drawn by the order they are listed in the block list. use ctrl arrow to move the inner most blocks to the top of the block list to force them rendering first.

 

if that fails to a degree, as it still blinks out from some angles, it's you alpha set up. I would have to go through your alpha flags to get it set up correctly.

[Jeoshua]

So hey, Quetz. In the interest of completeness.

 

Did Ghogiel's suggestion of moving the nodes work? Does this fix the problem and let you layer alphas in the way you needed? My knowledge of Nifs is a bit outdated, set in the Morrowind era, and I'd really like to know if they've updated the engine so that this kind of stuff is finally possible.

[Quetzlsacatanango]

I don't know yet.

The oscillator thing is actually a different armor item. I could join them I guess, reorder the blocks, and see what happens. I will update when I do.

[jonnyeah]

WJS and I have fought with alpha quite a bit, and have decide there's only really three practical solutions.

 

1: Redesign things to avoid having multiple overlapping alphas.

2: If the alpha is to save on absurd poly count (like grass or something), an alpha setting of 4844 (binary alpha) will allow rendering to work normally. You'll want to play with the threshold to get things as smooth as possible.

3: Kinda painful, but simply cutting the outer alpha into multiple nitrishapes/strips will reduce the number of angles where the inner alpha won't render. You can find proof of layered alpha rendering on the Q-35, look at it from the front then behind, one side renders but the other doesn't for some reason.