Allows you to specify whether the UI Image should be displayed using the mesh generated by the TextureImporter, or by a simple quad mesh.
When this property is set to false, the UI Image uses a simple quad. When set to true, the UI Image uses the sprite mesh generated by the TextureImporter. You should set this to true if you want to use a tightly fitted sprite mesh based on the alpha values in your image.
Note: If the texture importer's SpriteMeshType property is set to FullRect, it will only generate a quad, and not a tightly fitted sprite mesh, which means this UI image will be drawn using a quad regardless of the value of this property. Therefore, when enabling this property to use a tightly fitted sprite mesh, you must also ensure the texture importer's SpriteMeshType property is set to Tight.