I want to edit the ToolMaterial on an item arbitrarily, is there any function that can update the ToolMaterial after it's been registered, or any method of working around this?

Reflection, my friend.

http://www.minecraftforum.net/forums/mapping-and-modding/mapping-and-modding-tutorials/2151027-1-7-x-using-reflection-to-modify-vanilla-values

They don't necessarily have to be Vanilla values.

From the end of that post, it seems that reflection is only really needed for efficiency and harvest level?  What's the call for attack damage?  But that's very useful anyway, thanks for that. 

Glad to be of service.

My material is created and registered in Main.class, so would I want

 

ReflectionHelper.setPrivateValue(Main.class, Main.material, x, y);

 

because when I try to do that, setPrivateValue errors, saying

 

The method setPrivateValue(Class<? super T>, T, E, int) in the type ReflectionHelper is not applicable for the arguments (Class<Main>, Item.ToolMaterial, float, int)

 

One more thing, when I do the field listing for Main, it doesn't give the fields for the tool material, just the tool material itself.

In this case you should use a Material as the second-to-last argument, not a float, since you are setting a Material variable.

Do you mean that I should create a new ToolMaterial with the modified values and give it as the second to last argument?  That gives the same error, with Item.ToolMaterial instead of Float.

You're not supplying it with the correct arguments. That's why it's "not applicable for the arguments".

I figured the reflection out shortly after posting that last reply, but it turns out I never needed it.