play a animation backward in mecanim system

If i want to play a clip forward or backwar in old system, it’s easy to do.
void Update () {
if (IfMouseClickOn ()) {
anim [“door1”].speed = Input.GetAxis (“Mouse X”);
anim.Play (“door1”);
} else {
anim [“door1”].speed = 0;



the code above means that if i move mouse from left to right, the clip will play forward with the same speed as my mouse, vise versa(play backward).
The question is, in mecanim system, we can no longer use anim[“”].speed=-1 to controll it. It’s seems
i need to do something with “AnimationRecord”? im not sure and a little confuzed.

This question has been answered quite a few times already. A quick google found this list of posts
which included this and this.

Too paraphrase them,the speed of the animation controller can’t be negative anymore, however, you can create a float parameter and assign it as the multiplier for any states whose speed you want to change as shown here.