How to make your own alpha textures and use them in Blender?


In this tutorial, I will be using Photoshop to create alpha textures (the methods I’ll be showing here apply to any other image editor paid or free) and discussing how we can use these textures in Blender.

Things to pay attention to before we begin

  • It is recommended to set the resolution of the image we will be creating to a 1:1 ratio, such as 2048×2048 pixels. This aspect ratio facilitates easy usage on various other applications.
  • Set the background of your document to black (so that, in other softwares such as Blender, the background will appear transparent).
  • Remember that the higher the quality of the reference image, the more detailed the final result will be for our alpha texture.

Let’s Begin: Launch Photoshop

  • Create a new document with dimensions of either 2048 by 2048 or, if desired, a larger size such as 4096 by 4096.
  • Set the background of the document to black.
  • Bring the image that you want to create alpha texture from into the document we just created.
  • Select the layer of the imported image, navigate to the top menu labeled as “Image”, then select Image Adjustments > Posterize

Note: If the options mentioned above are greyed out, it means that you did not select the correct layer.

Posterize function helps making the details of the image pop, and eliminates the huge differences in color range, so we do not have details that are extremely eye-straining. (Suggested values to use here are: 2, 3 or 4. The key point is not having something too harsh.
  • Next step: Image > Image Adjustments > Black and White (Set all color values to 300 and press okay)
  • If the image got too harsh, you can apply gaussian blur. Suggested value for this effect may vary from 1 to 8.
  • If you want your image to be very crunchy, you can bring a “Levels” layer and apply the adjustments you desire.

Note for people who are not familiar with Photoshop: Bringing the handle that is located on the left side (The one that appears darker) to the right side will make the black parts pop. And the opposite (Moving the white handle from right to left) will do the same thing for the white areas.

“Levels” in action

Next step (The Fade Effect) is optional, but I highly suggest doing it if you are not going to use the texture with the method of “Stencil” in Blender.

The Fade Effect To Create Soft Corners

  • Merge all of your layers in your Photoshop document, except for the black background. (After the merge, the image will lose some of its popping details but it’s normal.)
  • Bring a mask, then invert it by pressing “Ctrl + i”. After you do this, you’ll see that the whole layer becomes hidden. It’s okay, this is the expected behaviour.
  • Switch to the soft brush, and press “Alt +Right mouse click” to adjust the size of the brush. Make it big enough that it almost overflows the texture.
  • Click in the middle of the screen once or twice, and that should be enough to achieve the soft corners we desire.

Note: If you want to make sure you’re clicking right in the middle of the document, you can create a Photoshop guide. This can be achieved by following the path of View > Show > Guide. If this area is greyed out, it means that Photoshop doesn’t have a created guideline. To fix that, you can just follow the path of View > New Guide. You can create a vertical, and then a horizontal line and can move them around when the move tool (v) is activated.

Final texture should be looking like this

Note 1: You can save this image in either PNG or TIFF format, or simply save it as a PSD file. Blender is capable of opening PSD files and utilizing the image content directly from within the file. If you saved your file in an image format such as PNG, and are facing problems, export it in 32-bit instead of 16-bit. Although I haven’t personally encountered any issues with exporting in 16-bit, I’m including this recommendation in case anyone else experiences any problems.

Note 2: Keep in mind that in order to see the effects of these brushes on your model, you’ll need to use a mesh with a significantly high polygon count.

How to use alpha textures in Blender?

  • Switch to sculpt mode.
  • Texture properties > New texture > Select your texture

Select the brush that you’d like to use from the left toolbar and start sculpting your the details over your model. Some suggestions for novice carvers:

  • If you want to use the texture we created as a brush, so you can paint the details all over your mesh, set the mapping technique to view plane by following the path of: Texture > Mapping > View plane. 3D method can also create some magnificent results. (Note: If view plane method is not working as expected, make your brush really big then try it again. 3D method for some reason only affects the middle of the mesh for the time being so be aware of this limitation.)
  • If you want to apply the details at one specific part on the mesh, you can switch to stencil mode by following the path of: Active Tool and Workspace Settings > Texture > Mapping > Stencil. If you’ll switch to stencil mapping mode, I suggest changing the stroke method to anchored by going to Workspace Settings > Stroke > Stroke Method: Anchored so you can drag over the texture for it to appear on the model. Here lies an issue with this method though: For anchored mapping method to work properly, sometimes you need to drag your mouse from left to right or right to left, until the cursor goes out of the workspace window. Keep dragging it until you see the effects appearing on the surface of the mesh. I suggest that; rather than increasing the brush strength, experiment with this mapping method if you’ll rely on it too much to figure out how it exactly works. In some cases you might really need to drag it a lot.
  • If you want your brush to be sharper, you can increase the strength of it or change the falloff value by going to: Workspace Settings > Falloff > Sharper
  • A general guideline 1: When brush strength is set to 1 (the strongest value), in most cases it pulls or intrudes the vertices too strongly, which ends up looking very harsh or ugly. In certain situations, it may be necessary to utilize a strength value of 1. In such cases, if you are employing a stencil mapping method, it is advisable to perform the action slowly rather than rushing it, as this will allow you to observe the results more effectively and maintain greater control throughout the process.
  • A general guideline 2: If you’re going to bake your model into a low poly one, add the details more harshly/deeper than you think you need because when you bake the details, you’ll lose a lot of them.
Final result, achieved via Texture > Mapping > View plane method.

Last updated: September 20, 2023

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