Visible

Explanation
The visible local variable is the variable that defines whether an object is visible or not. This can also be changed in the object properties window.

Setting visible to false is the same as setting image_alpha to 0.

Examples
The variable visible can be used to make an object temporarily invisible, without destroying it. This can be useful for levels with advanced layouts. To have effect though, you would need to set solid to false also. if (disabled) {  visible = 0; solid = 0; }

It can also be used for something like an invisibility spell (although using image_alpha is probably better). if (invisible) {  visible = 0; }