View Full Version : How to merge Textures in Photoshop

10-26-2005, 03:05 PM
Hi all,

Whats the best way to merge 2 texture maps together? Let me explain. I have an Orcish character that I have applied a nice gray Elephant skin photo too. It looks great on his Dorsal/Back side but it's "too much" to apply to his Ventral or Abdominal side. He needs a softer underbelly. So I'd like to add a different and softer gray texture map (from Photoshop) to apply to his belly. I'm using UV's obviously for this but I know I'll get a harsh seam if I apply 2 different tex maps to his back and front where they meet. The entire Torso has 1 UV map so how would you guys go about solving this problem?

Would you try to apply 2 different textures to 2 different UV maps?

Or would you use only 1 UV map and apply 2 textures? Or is there another way?

Thanks for the help.


Captain Obvious
10-26-2005, 03:22 PM
I would create a new higher resolution image in Photoshop and add both images to it (use clone stamp and all that to smooth out and correct everything), and then apply it using a single UV map.

10-26-2005, 03:54 PM
Okay a few different options:
Make sure your belly has some overlapping polys in it's UV map (overlapping in terms of covering the same polys) Then add an alpha to it, and load it into LW. The alpha channel of a texture in LW behaves differently from something like Maya, in that it acts like a sticker sillouette, masking out the bits you don't want. This is fairly easy :)

You could use ANOTHER UV map which has all the body UV mapped in it, and paint white where you want one texture and black where you want the other. Then add it above the texture which is supposed to be in the white part and change it's blend type to alpha. This makes it behave like an alpha mask as above, masking out the surface in the areas you want.

Alternatively, if your mesh is dense enough, you could paint a weightmap, having 100 percent for one texture and 0 percent for the other. Add a gradient above the one map, and set it to Weightmap, selecting your weightmap. Set it's blend type to alpha, as above, and it'll fade out the texture in the 0% areas.

There's loads more ways...

10-31-2005, 11:43 AM
Sorry but I'm not sure what you mean. Do you mean add a Texture with a Blending Mode of "alpha"?

If so what Layer Type would I use? Do you mean go into Photoshop and paint a white spot on my character's abdomen for example over a Black background and then load this into LW as a mask?

Havent done any of this before.


10-31-2005, 05:32 PM
Basically an alpha is a way of masking an image out in parts using two colours, usually black and white with the convention being white=apply all the image, and black, apply none. In LW you can do this masking out in multiple ways.

1) In the image itself. You go into the channels palette in photoshop, and add an alpha layer and paint white in that where you want the image to be fully opaque. Save it out as a 3-bit image in a format such as .tga, and load it into LW. By default, if you apply that image to a surface, then the image will be masked out on the surface in the black areas, fading in as the alpha goes to grey and fully opaque at white.

2) make a separate black and white image, which you load into LW as well as the texture, and you apply the image in the colour channel, then add another texture layer on top, into which you put the alpha image. Set the blend type to alpha, and this will be like adding the alpha to the image in photoshop.

Basically try it and see :)

Safe Harbor
11-01-2005, 09:12 AM
I'm not a LW user, so please pardon me if this is not usable advice. I am a graphic artist and use Photoshop constantly. When I'm trying to blend two separate images, this is what I do:

Put each image on it's own layer.

Move them around so they overlap a bit.

Select the eraser tool, and choose a large soft edged brush. Set the opacity to something very low, like 20%. Start erasing the top layer at the overlapping edge. You'll start to see the layer below it.

Adjust your settings and brush size as needed until you have the blend you want.

I hope this helps!

11-01-2005, 08:18 PM
To put it in Photoshop terms as closely as I can, Alpha layers act as Masking layers do in Photoshop. Say you create your two images and elect to mask out the top layer to show the layer below. You have the ability to determine the bluring at the edge of the mask so that the two images merge "seamlessly".

In Alpha terms, the area where your image is showing is white, the transitional points are varying points of gray, and the mask which would block out the other layer is black.

That's about the best Photoshop analogy I can come up with. Essentially by creating Alpha's you're creating the mask layers to tell which images to shown when and by how much, just as you would do if you're masking.


11-01-2005, 09:13 PM
The attachment shows an alpha used as a mask. This allowed me to fill the background with a wood pattern. Alphas are important in video editing software as well, as it allows you to overlay objects on moving video.
But like Hoop says the alpha can be a gradation which makes a blend between two images.
Edit: I added an additional image showing a gradation.

11-08-2005, 09:36 PM
Sorry I've been away recently. But thanks for the instruction.

I'll give it a try next week. When I complete my first scene I'll post a picture of it for all of your opinions.