Koru materials have lots of parameters that can use textures, like reflection, bump, mask and so on. Almost everywhere you can also provide a tint color or a multiplier. Here’s what it looks like:

Texture control in Koru material

The top one (Bump) has a multiplier, while the bottom one (Color) has a tint color instead. Both controls have texture boxes at the right. That’s the same image, explained:

Texture control in Koru material explained

By unchecking the box between the multiplier/tint field and the texture box, you can disable the texture for that parameter. In that case, only the tint or multiplier value will be used.

If you load an image to the texture control, it will change its appearance. Here we loaded image into the bottom control:

Texture control in Koru material with loaded image

As you may see, the bottom control displays a “picture” icon in its texture box, showing that an image is loaded there. You can drag that texture box and drop it to another control that accepts textures to copy the image with all its settings to that control.

Texture Editor

By clicking the texture box you open the texture editor window:

Texture editor window in Koru

Here’s what you can configure here:

Source section

  • File - that’s the file picker that you can use to pick a different image file, if you like. You can also drop an image here or use the “cross” button to remove the image;
  • Invert - by checking this you invert the image;

Color correction section

Here you can make a simple color correction of the image by adjusting brightness, contrast and gamma levels. As with other settings, this affects only this exactly parameter, so the same image loaded to a different material will stay intact.

Mapping section

Koru can shift, tile and rotate textures in each slot. Here you configure it using the controls below:

  • Offset - lets you control how much the image should be shifted. Note that this is in UV coordinates, so shifting by 1 means no shifting and shifting by 0.5 means “half”;
  • Repeat - controls the texture tiling, where 1 means “no tiling”, 2 means “double” and so on;
  • Rotation - rotates the texture, the angle is defined in degrees;
  • Wrap - lets you choose what to do if texture coordinates run out of [0; 1] range.
  • Filtering - controls texture filtering mode;

Wrapping options are:

  • Repeat - do nothing, simply tile the texture. That’s the default option;
  • Clamp - clamp the texture running out of the [0; 1] range. Koru will use the edge pixels of the image to fill all the parts with texture coordinates out of range;
  • Mirror - that’s pretty much like clamp, but instead of stretching Koru will mirror the pixels, so areas with out-of-range texture coordinates will get a reflected copy of the texture.

Filtering options are:

  • Nearest - no filtering is performed at all. Good for pixel-art and related graphics;
  • Linear - linear filtering, used by default.

Crop section

Sometimes you just need a part of the image. That’s where the crop helps. You can define the rectangle of the image you want to use, using Left/Top/Right/Bottom fields. Note that the parameters should be in [0; 1] range, as these are UV coordinates.

The difference between crop and repeat/offset approach is that crop works before repeat/offset and you can easily tile cropped image without risk of seeing the parts that should be cropped.

Other Parameters

Sometimes (for bump images) texture editor shows a different set of parameters, mostly by removing the color correction section and adding a height/normal map switch, which is essential for bump.