Preventing obvious tiling of textures
Example of a brick wall: Problem with the use of digital photographs as textures is the effect of tiling. This means that if the texture is tiled on an object we can see the repetition of parts of the image which differ in color to much from the rest of the image. This is called tiling. This effect is a big no-no in computer graphics and should always be addressed.
Using the 3D texture Crater to prevent tiling
A quick but effective method is to use one of Maya's default procedural textures that mixes three inputs (color or other textures) using a mathematical procedural pattern.
- In the Hypershade, create a node.
- Assign the Crater node to the diffuse color property of your shader
- Assign the shader to your object.
- Select the 3D crater in the hypershade and open the attribute editor.
- There are three color options in the color settings of the 3D Crater.
- We will replace each color with a variant of a photo of a brick wall ( these are variations of a single photograph of a brick wall altered in Photoshop to change the amount and position of bricks which differ to much in color and cause tilling).
- The effect is a non tillable material.
Using a Layered Texture node
You can use the Maya Layered Texture node to mix/blend two or more textures using a custom pattern or blending mode.Hypershade, create a node. By default it has one channel, set to a single green color.
To add your textures to the layering node, MMB-drag them to area with the red border.
The left-most item is the top of the layered stack.
To control whether or not underlying layers will become visible, you can use:
- Controls the transparency of the layer. If it becomes transparent, the underlying layer(s) will become visible. In most cases you would use a texture to control the alpha.
- Blend Mode
- Layers can be blended with those below them using the Texture Blend attribute. The Blend Mode specifies how the selected layer blends with the below it.
Please remember to think about the best way of controlling the projection of the alpha texture. Should it be the same as one of the other textures, or do you need a separate placement? Don't forget to enable Alpha is Luminance if you're using a gray-scale image.
From the Autodesk Maya 2015 Help:
- Edits or paints each pixel to make it the result color. This is the default. (Normal mode is called Threshold when you’re working with a bit mapped or indexed-colored images).
- The top layer is applied like a decal to the following layer. The shape of the decal is determined by the top alpha.
- The background texture is cut in the shape of the foreground alpha.
- The result is the opposite of In. It is as if the shape of the foreground layer has been cut out of the background alpha.
- The result color is the foreground color added to the background color as if being projected on the background through a slide projector. The result color is then applied over the background color using the foreground alpha to define the opacity of the result.
- The result color is the foreground color subtracted from the background color. The result color is then applied over the background color using the foreground alpha to define the opacity of the result.
- Looks at the color information in each layer and multiplies the bottom color by the blend color. The result color is always a darker color. Multiplying any color with black produces black. Multiplying any color with white leaves the color unchanged.
- Looks at the color information in each layer and subtracts either the blend color from the bottom color or the bottom color from the blend color, depending on which has the greatest brightness value. Blending with white inverts the bottom color values; blending with black produces no change.
- Looks at the color information in each layer and selects the bottom or blend color, whichever is lighter, as the result color. Pixels darker than the blend color are replaced, and pixels lighter than the blend color do not change.
- Looks at the color information in each layer and selects the bottom or blend color, whichever is darker, as the result color. Pixels lighter than the blend color are replaced, and pixels darker that the blend color do not change.
- Creates a result color with the luminance and hue of the bottom color and the saturation of the blend color.
- The result color is the background color with saturation decreased in proportion to the foreground color scaled by foreground alpha. If the foreground color is red, for example, the resulting color is the background color with desaturated reds.
- Creates a result color with the hue and saturation of the bottom color and the luminance of the blend color. This mode creates an inverse effect from that of the Color mode.