September 28, 2012, 12:54:39 pm
Hi Mischa, this problem can be fixed if you have Photoshop and the Nvidia Texture Tools
The reason that the problem occurs is due to mipmapping
(see below) and the fact that Lumion only uses 1-bit alpha transparency for opacity masks.
Pure white pixels on the alpha mask means that those pixels will be fully visible, and pure black pixels on the alpha mask means that those pixels will be invisible. If a pixel is somewhere between black and white, it will be rounded up or down to black or white.
As the camera moves away from the fence, the smaller mipmaps of the fence texture will be used, and those are scaled down so much that they're no longer white and black but greyish pixels that are closer to black than to white. For that reason, the texture will be fully invisible as the camera moves away.
So, bearing that in mind, how do you work around this problem?
Well, you need to manually make the visible pixels on the smallest mipmaps white instead of greyish, so that Lumion doesn't round them down so that they end up being interpreted as invisible when you move the camera away.Here's how:1)
Install the Nvidia Texture Tools
plug-in for Photoshop.2)
Make sure that your texture width/height is a power of two, e.g. 8/16/32/64/128/256/512/1024 pixels etc.3)
Save your texture including the alpha mask as DDS (RGBA format: 126.96.36.199 )4)
Load this texture again (Load Mipmaps
Edit the smallest mipmaps so that the pixels that you want to show up in Lumion are white on the alpha mask.6)
Save the DDS texture again (MIP Map generation -> Use existing MIP maps)TIP:
For those of you who don't know what mipmapping is, please read the "How it works
" section here:http://en.wikipedia.org/wiki/Mipmap