renderer.material.color.a

[Trorlroprlro]

I’m having a problem with this:

  void Update(){

	var staticObject = GameObject.Find("staticObject");

	if(staticObject)
		{

			staticRenderer = staticObject.renderer;

			staticRenderer.material.color.a = 0.0f;
		}
		else
		{
			Debug.LogWarning("Not found");
		}
	}

It gives me:

Cannot modify a value type return value of `UnityEngine.Material.color'. Consider storing the value in a temporary variable

How can i fix this?

[Spinnernicholas]

staticRenderer.material.color is a property, that means it is basically a function and it returns a Color struct. Because Color is a struct, and not a class, you get a copy. Changing the copy does absolutely nothing to the original.

If it were a class, you would get a reference and you could modify it like that you are trying.

The common form for what you are trying to do is:

1. Retrieve the original.
2. Modify it.
3. Store it back to where it was.

Here it is in code:

Color color = staticRenderer.material.color;
color.a = 0.0f;
staticRenderer.material.color = color;

It is sometimes a good idea to create helper functions to make it easier.

function changeAlpha(var color, var newAlpha)
{
  color.a = 0.0f;
  return color;
}

Then you could use it like this:

staticRenderer.material.color = changeAlpha(staticRenderer.material.color, 0.0f);

[Subhajit-Nath]

In C# you need to write it like this:

staticRenderer.material.color = new Color(1.0f, 1.0f, 1.0f, 0.0f);

[Key_Less]

The alpha channel in the color component is readonly and cannot be assigned. So if you only want to change the alpha value, you’ll need to store the color in a temp variable as the error suggests, then change the temp and reassign the color value.

var color = staticRenderer.material.color;
color.a = 0.0f;
staticRenderer .material.color = color;