Sculpting alpha brush does not work

Development Pipeline & Plugins
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1

Hello, I am currently working on a landscape, and I want to use the sculpting alpha brush tool to make some mountains and hills, but when I tried dragging the image onto the little pannel where you drag & drop your images it shows up green BUT when I release the LMB it is just the DefaultAlphaTexture and not my image.

252948-3.jpg
252948-3.jpg1920×1080 319 KB

So I tried another image, wich is also b/w and this works.

252949-1.jpg
252949-1.jpg1920×1080 306 KB

I checked the “description/details” of both images and they’re identical.

252950-2.jpg
252950-2.jpg1920×1080 305 KB

So I don’t know what is wrong… Could anyone help me?
(I apologize for my bad english)
thanks :slight_smile:

1 Like
2

I’m having the same issue. If anyone has a solution please let me know!

3

I also am having this issue. Hope they can address it soon.

4

You must save your alpha as 8 bit before importing to UE4.

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5

You must save your alpha as 8 bit before importing to UE4.

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6

The texture must have the following qualities to be used as an alpha for sculpting landscapes:

  • RGB, or RGBA. Greyscale does not work.
  • 8bit.

The image format is not restricted to TARGA (.tga). PNG and JPG works too.
Non-Square resolutions work as well.
The compression format does not matter.

I personally use substance designer for texturing. In this case, you would make sure that the output format is “C8.”

1 Like
8

Hi.
I was using UE5 and try to create landscape with alpha. And i’ve got the same problem.
I’ve tried two days, finally I realized if you import a .png file to UE5, no matter how you set the picture format, whether if it is a 16 bit or 8 bit , RGB or Gray, it just doesn’t work. But if you import a .jpg file it will magically work. Maybe .tga file will work too? I didn’t tried that.

I’m not sure about if it’s working on UE4. Cause I 've never noticed someone mentioned this. So I believe this is a bug.

3 Likes
9

It turns out that PNG files do NOT work as alpha brushes, but TIF files do.

I had 4K, Grayscale, 16-bit Non-Linear Integer images that were not being recognized in Unreal 4.27.2. Re-exporting the same image from GIMP with the exact same settings as above but as a .tif file (using “Deflate” lossless compression for the smallest file size) allowed Unreal to use the image.

Sadly, regardless of export settings, Unreal appears to only interpret Landscape brushes as 8 bit, regardless of texture compression settings, so setting to HDR or Half-Float appears to makes no difference compared to just using Grayscale or Alpha presets. Thankfully, you can smooth the result afterwards. Setting the “Filter Kernel Radius” for the Smooth brush to 1 and checking “Detail Smooth” and setting that to a small value like 0.01 works great for smoothing out blocky noise details.