Alpha weirdness in Max 2010
polycounter lvl 19
(This problem was solved by Eric Chadwick and frubes in two different ways so I renamed the posting title so other people who run into this issue can find the solution. Basically you need to make sure the DIFFUSE map's "alpha source" is set to "none" or separate the opacity and diffisue maps into two different textures)
Hey all. Just upgraded to Max 2010 and I'm experiencing some weird rendering issues with alpha transparency for materials (tga) that I never experienced in 2009.
I've opened my project that I was working on in 2009 and now for some reason my transparencies all have this weird outline around them that wasn't there before. I added a copy of the alpha channel from Photoshop to the top of the render to show what it should look like. The grass plane should blend perfectly with the background but instead its got a lighter outline around the entire plane.
They also don't look like the textures are rendering with as high quality as they used to. Anyone know what might be causing this?
Thanks!
Hey all. Just upgraded to Max 2010 and I'm experiencing some weird rendering issues with alpha transparency for materials (tga) that I never experienced in 2009.
I've opened my project that I was working on in 2009 and now for some reason my transparencies all have this weird outline around them that wasn't there before. I added a copy of the alpha channel from Photoshop to the top of the render to show what it should look like. The grass plane should blend perfectly with the background but instead its got a lighter outline around the entire plane.
They also don't look like the textures are rendering with as high quality as they used to. Anyone know what might be causing this?
Thanks!
Replies
You can change the texture resolution in Customize -> Preferences -> Display Driver Settings menu. Change the "download texture size" and "background texture size" to the max, and also make sure "match bitmap size as closely as possible" is checked for each.
I tried changing the texture sizes in the graphics settings and it didn't make a difference. Any other ideas? I'm rendering with D3D 9.0
Graphics card drivers up to date?
If you're rendering, it could be that the Diffuse bitmap has its Alpha Source set to Image Alpha, so it's pulling in some of the plain diffuse color from the material... setting it to None should solve this.
There are no scene effects or anything else. I'm using the default 2010 settings with the default scan-line renderer.
I did some more tests, with a completely new scene and found that regardless of having a scene background or not and regardless of whether the alpha map in the texture (photoshop) is a soft fade (feather) or a solid outline (single pixel) it still has a glow around the outside of the image when rendered.
This alpha channel in Photoshop...
Gets these results in Max 2010:
Even with a solid outline for the alpha there's still a glow:
I also tried changing the Alpha Source to None and that only changed the way it displayed in the viewport.
My current settings for the Opacity are as follows:
This is really confusing.
I just updated my graphics card drivers and this made no difference. I tried switching to OpenGL from Direct 3D and this also did not make a difference. This leads me to believe that its definitely a setting in max 2010 or maybe a change in the default scan-line renderer?
If thats the case try and save the alpha and the diffuse as two seperate textures. So you have a diffuse with no alpha, and the opacity map as a texture in its own right and load that into the opacity slot.
If that doesn't work trying saving as something other than a tga. I believe there is a bug with .tga files and alphas but i dont know if it still applies to 2010.
Thanks to everyone for your help!
(I'm changing the name of the post title so anyone else who has this issue can find it better in search results)
You only showed your settings for the Opacity Bitmap, which I think won't actually fix the problem you were seeing. Of course splitting them into two textures will work, but it should be possible to fix just by choosing the correct Alpha and RGB output settings for both the Diffuse and Opacity Bitmaps in the material editor.
EricChadwick correctly diagnosed this, although I think you misinterpreted because you gave a screenshot of the Opacity map, not the Diffuse map, so I think you were looking at the wrong Bitmap settings.
Should be useful info if you need to get this working in future (maybe try it again now just to make sure it works).
(Max handles the different Channels of a Material sequentially...the first thing to be computed is the Diffuse Channel, so with an Alpha Channel you'll get a Halo with the default color around your circle. Then the Opacity willl be added, and you have a semitransparent Halo, since the Opacity Map Cannot eliminate the default color of the Material. In case of your second circle, the one without any gradient, you might get away with deactivating the Texture Filtering, though I haven't tried it...)
Edit: MoP...Great Minds think alike :poly142:
Means you can use the same UV coordinates for both without having to do a 2nd channel for the placement of the sticker - just place it through the Bitmap settings.
You're absolutely right MoP, I DID misread Eric's post and changing the diffuse alpha to "none" did fix the problem. Its weird cause I've been using this method in max for years and its never been an issue until 2010. I guess its probably due to an improvement in the renderer because technically I should have run into this issue years ago
Thank you guys so much for figuring this out.
Anyway, good that it's sorted out