How to make holey textures?

Question

Blender

In games, you can often find leaky textures, probably this is done to save resources. For example, a picture, where the blades of grass seem to have a shape, but do not collide with other objects. How is this done? And even called culturally?

Answer 1

I do not understand. Perhaps you are referring to the transparency channel or alpha channel, which is available when using the .png, .tga, and other less popular formats. Although when creating textures in a 3D editor, you can use pictures with any extension, and set alpha as a separate black and white image, but for me it’s more convenient to use one texture for both color and transparency.