Alpha texture "bleeding"

[Nadnerb]

Even if you only use alpha values of 1 and 0 in your texture, when displayed by the engine, it will 'filter' the texture when viewed at greater than it's native resolution by interpolating all the colors, including alpha, and mipmaps will also, being scaled and filtered versions of the original texture, have partial alpha values, so unless your model is z-sorting perfectly, it is impossible to eliminate this effect completely.

[Trylon]

I'm not sure if that's caused by the engine or by pyprp.

[Nadnerb]

Well... if referring to the mipmaps, then yes, it's caused by the plugin, but only because it is working correctly. You can tell the plugin not to generate mipmaps, if I recall correctly. Mipmaps, however, are useful for rendering distances. Perhaps there could also be an option to 'clamp' the alpha values in mipmaps to integer values. however, the other effect, (filtering at short range) is a function of the engine, which I'm not sure you can change. While we're on the subject, I'll note that you can find this effect in Cyan made ages as well, and they've likely tried pretty hard to eliminate it. Basically, unless you can guarantee that your objects will only be seen from certain angles, for which a single z-sorting will work, this will show up.

[JulyForToday]

Have you tried just not having a semi-alpha texture?

That sort of defeats the purpose. Some things that would be fine with, but other things you'd want to be able to have it semi-transparent.


Although it may be impossible to actually 'fix' this issue, the intentional sorting of the z-buffer would be largely helpful in being able to reduce these kinds of defects. So is there a way to explicitly set the z-buffer's order? I posted before about the naming effecting it, but I can't seem to get it to work 100% of the time, so I'm not sure what is really controlling the order they get drawn it. Something like my sky would be totally fixed by specifically setting the z order.

[Trylon]

Yes and No,
there is a way to set it in plasma (I think), but it's not in the plugin (yet).

[Paradox]

Just a question that popped into my head: Is every leaf an individual object?

What happens if you put all of the leaf patters into one big texture, and make all of the leaves for a single tree one object with leaf-specific UV coordinates?
That might solve the issue of which object is rendering first (since they should all render simultaneously).

[Nadnerb]

Just a question that popped into my head: Is every leaf an individual object?

What happens if you put all of the leaf patters into one big texture, and make all of the leaves for a single tree one object with leaf-specific UV coordinates?
That might solve the issue of which object is rendering first (since they should all render simultaneously).

That would be a great big NO.

Polygons are rasterized. No matter what, polygons are always drawn separately, regardless of whether they're part of the same object. I would guess that, currently, the order they're drawn in is simply the order they're written to the file. Currently it seems ambiguous as to how the blender draw order translates to the plasma draw order. In fact, if one could find a way to properly specify this, it might actually be better for all the leaves to be separate objects. The way that I get objects to z-sort properly in blender is to "make parent" the object that I want to be drawn first, and then immediately clear the parent, leaving the objects in a different draw order. This would help if objects were written to the prps in the order they're stored in the blend file. However, this is untested. Perhaps somone could test that.

[Aloys]

I spent quite a bit of time working on this lately for Ahra Pahts, and as of now I haven't been able to find a solution that works every time..
I tried renaming the files different ways and couldn't get it to work. Also during one version my lightflares worked fine, and then for the following version I couldn't see them anymore although I hadn't touched them at all..
Now, even the sun is gone in Ahra Pahts..

[Grogyan]

I have a small idea, why don't you use a shade of grey instead of white for the edge of the texture, or not use white at all and leave the texture with a sharp edge or blur the sge with the colour of the texture?

I just had a look at JangaLela, and it uses a lot of alpha transparent textures, and all of them use white to blend the texture.

[Marcello]

Considering the z-buffer order solution...

I always assumed this should be possible. Every time Cyan uses a decal (like the Yeesha symbol on the wall and floor in our Relto hut, the decals on the floor in the City, etc.) the underlying mesh and the decal mesh are in the same spot. No noticable difference in height to force an order. So yes I think Plasma does accept some way to influence the rendering order. I'm pretty sure it happens in the examples I mentioned. (Nothing technical to back this up ).