Mipmapping vs. alpha

[animats]

I'm making a low-LI air kraken weathervane for the New Babbage oiling festival.

The vane is just two flat surfaces of two triangles each, with a Photoshop-created texture.

This needs hard edges, since it will be silhouetted against the sky. It should be clearly visible at long range, so it needs to look good at low level of detail. Looks fine in close-up.

At long range, it gets fuzzy. Even thought the roof does not. This is, I suspect, mip-mapping in action. Mip-mapping applies to the alpha channel as well as the color channels, so the area covered gets blurry. The roof is blurred, too, but because it isn't using an alpha channel to define the edges, it doesn't look so bad.

Suggestions on how to do this better? If I modeled all those tentacles, the triangle count for low-LOD would go way up.

Edited September 1, 2018 by animats
Explain why not a detailed model.

[OptimoMaximo]

Use a tga defined alpha map, with the color channels padded to infinity outside of the alpha opaque region. That shuold help a little

[animats]

Resizing, and using a lower resolution texture, helped.

R

Clockhaven, New Babbage. Temporary installation atop a large power station. New Babbage is always rather dark.

Close up. The letters are also images on flat surfaces. Both arrow and letters are monochrome images with an alpha channel.

Quote

Use a tga defined alpha map, with the color channels padded to infinity outside of the alpha opaque region. That should help a little

Ah. I checked the .png file, and if I remove the alpha channel, it's white outside the clip region. I should make it dark grey. Then areas at the edge of the mask will go grey, rather than lighten, and mip-mapping won't make it look thinner. Thanks.

[Kyrah Abattoir]

Consider switching to alpha mask mode if you want sharper edges on your alpha. But you'll have to make sure that the edges of your diffuse/alpha are very clean.

[Cathy Foil]

If your texture is square like 256 by 256 try using a 64 by 1024. 
Stretch your image to fit 64 pixel high by 1024 pixels wide. 
This should help keep your image from getting bury at a distance.

Hope that helps.
Cathy

[Beq Janus]

As Kyrah suggested, alpha mask whenever possible. That said you lose any antialiasing in doing so and that might degrade the effect overall. 

Optimo suggested alpha padding but didn't really explain what he meant, what he may have been alluding to is the practice of bleeding the colours around the masked areas, this is best known for removing the white halo as noted in the tutorial below, but it also has implications for mipmapping because of the way that the sampling occurs in openGL.(In general, the viewer should default to Anisotropic sampling, but that will vary by graphics capability)

One of the best tutorials on this is by Robin (Sojourner) Wood and it makes use of the free Flaming Pear photoshop plugins, if you are not able to use PS, those plugins are (I believe) usable within Gimp. http://www.robinwood.com/Catalog/Technical/SL-Tuts/SLPages/WhiteHalo1.html

The tutorial is two pages, the first page guides you through the problem itself and the second demonstrates the solution.