Hello,
There is a great tutorial that describes the idea of
health bar, the problem it is in script so you can try and translate that into Playmaker. That is of course if the health bar is what you are referring to by the blood bar.
However to do the system like he did so that you can subtract the length:
First create and assign a variable, let's name it width for now and assign the width of the screen to it (use an action
Get Screen Width and store it in the variable)
Now create two other variables maxHealth (which is your maximum health) and currentHealth (current health you have now)
Create another action
Int Operator now divide the width by 2 and the result by the maximumHealth and divide that as well by the currentHealth (you will need three
Int Operators actions to do this)
Create a
GUI Box and assign the texture you want to it (in this case this will replace the
GUI Texture you made) and assign the
Width the width variable we created at the very start.
That should display a rectangle with the texture you want horizontally across the screen and will change according to the amount of the current health the play has when he is hit.
I hope this helped in anyway.