White edges around Decals

chrisjuuuh

First off, I apologize for spamming the UDK boards with threads adn questions lately. I do try and find the answers to my questions on google and such.



I'm now having trouble with decals... They have white edges running around the boarder of the decall. It has something to do with my transparancy mask as I have disconnected the diffuse, normal and spec maps and it doesn't go away. I have also checked my alpha channel in my diffuse which I use for the transparacy mask. and except for the areas i want to see it is completely black.

Im truly confunded and would appreciate any help.

sprunghunt

you need to set the address X and address Y properties to 'CLAMP' in the texture you're using. These properties are found when you double click on the texture to get something that looks like this:



where it says "TA_wrap" change that to "clamp"

chrisjuuuh

Hi sprung,

That doesn't seem to be working as what happens is when i set them to clamp the decal becomes invisible, except for the white lines which are still there. you should also probably know that I am using a single texture for three different decals. I don't know if thats relevant or not.

sprunghunt

chrisjuuuh wrote: »

Hi sprung,

That doesn't seem to be working as what happens is when i set them to clamp the decal becomes invisible, except for the white lines which are still there. you should also probably know that I am using a single texture for three different decals. I don't know if thats relevant or not.

If you're texture atlasing decals then that's your problem. What's happening is the edges of the alpha is bleeding between the three textures.

However there's absolutely no performance or memory advantage to atlasing decals.

Here are some reasons why atlasing isn't useful in this case:

1) UDK pauses at each object so there's no performance advantage to having more than one object using the same texture.

2) if you want to use just the manhole texture you're getting the other textures in memory anyway. This can be a waste of memory.

3) you're using extra shader instructions to achieve the atlasing. Shader instructions aren't free so save could yourself a bit of FPS by removing them.

So cut the texture up into 3 different textures and set them to clamp. Don't use a single texture for multiple decals.

chrisjuuuh

Hi Sprung,

Thanks for the lesson! ill seperate them out into different textures.