The newest Windlight viewer (released the day of this posting) offers a new graphics rendering performance optimization. At certain distances, the alpha channel of a prim's textures will be dropped, making the prim 100% opaque. This offers a performance boost, since other textures appearing behind an opaque object are not rendered. With the implementation in 77495, however, the results are often ugly. Sometimes objects as close as 10m from the camera lose their alpha channel. In my opinion, that is a bit too close. Also, objects with invisible (100% alpha) textures become opaque. Instead of being rendered opaque, 100% alpha textures probably shouldn't be rendered at all. Attached is a screenshot of a 30cm*30cm*30cm cube with 100% alpha sides and orange color sitting ~10m away from my avatar. The cube should be perfectly invisible, yet alpha culling makes it opaque at quite a short range. In both older versions of Windlight and the mainline viewer (which don't seem to have alpha culling), the cube is rendered correctly in all cases.