Decal is almost transparent in certain locations

Hello guys, I’ve a problem with decals.

I spawn this Material into the world:

through this C++ code:

The problem is that in some areas of the world the Material is visible, in other ones it’s almost invisible, why?

Thanks in advance!

Try switching your Decal Blend Mode from Translucent to one of the Deferred options, that should solve your problem.

It won’t work.

Also, when I go away from the decal, it starts disappearing…

It seems to be almost transparent when I spawn it in places covered by the shadows.

Meanwhile, in places hit by the light, it works fine.


Normal decals don’t work properly with indirect lighting, such as a skylight. To get decals to work with indirect lighting, you have to enable dbuffer decals in your project’s rendering preferences, and then switch the blend mode to one of the deferred options. I think you might also have to restart the editor after enabling dbuffer decals before they actually work.

It’s a known issue, and something that I think is a bit of an Achilles Heel for UE4 in some ways. You can vote for the Trello card here: Trello

So with skylight they don’t work.

Can I use other kinds of lighting which are not skylights?

I suppose you could light your scene entirely with direct lights. Give it a try and see if it works for what you need.

Just to narrow down the problem, try placing a standard decal actor with your decal material on the same surface. It could be that HitNormal is not aligning properly. Notice, that your diffuse texture is not showing up, only alpha works. Also, I am extensively using deferred decals with skylight (movable), and they work perfectly well.

I placed a decal actor on the wall and this is the result:

As you can see, even with a Decal Actor the material doesn’t show up properly.

Having this same issue in 2020

Hi guys, im having the same issue with the decals i downloaded in Quixel MegaScan Bridge. When i place it in my scene, there’s no color and its not showing as it is supposed to be.

Try to change sky light mobility see if that helps, for example how it looks on movable skylight?

Hi everyone! I just found that it can be a problem of lightmap resolution, you just have to increase it for the surface that keeps making the decal faded and tadaa !

Lightmap res is completely unrelated to decals. You do not want to do this, its actually harmful. You just have to rotate the decal and possibly check the materials.