Blueprint Mutator Tutorial - Low Grav

This tutorial will teach you how to make a Low Grav mutator for UT using only Blueprints. I over explained some blueprint mechanics to help those who are just starting out.

Requirements

• Engine version: 4.3
• Skill level: beginner

Create the Blueprint

• In the Content Browser, hit the new button.
• Select Blueprint from the dropdown menu.

• Enter UTMutator in the Search box of the Custom Classes box.
• Select UTMutator and then hit the Select button.

• Name the Blueprint "Mutator_LowGrav".

Edit the Blueprint

• Double click your new "Mutator_LowGrav" Blueprint to open it in the Blueprint Editor.
• Click the Graph button in the upper right
• Click the +V (Add Variable) button
• Change the variable name to "NewGravity", check the Editable checkbox

• Click the Compile button in the upper left of the window
• Click the Defaults button, then set the value of NewGravity to -250
• Return to the Graph view by clicking the Graph button again in the upper right of the window
• If you're not in the "Event Graph" tab, double click the EventGraph text in the My Blueprint panel
• Right click the empty graph and select "Add Event", then select "Begin Play" to place the "Begin Play" event
• Right click the empty graph again and search for "Get Game Mode", select "Get Game Mode" to place the "Get Game Mode" node
• Drag off of the "Get Game Mode" Return Value to bring up the node search box again, select "Cast To UTGameMode" to place our cast node
• Connect the "Begin Play" event to the "Cast To UTGameMode" node
• Drag off of the "As UTGame Mode" Return Value to bring up the node search box, select "Set World Gravity" to place the node
• Drag the NewGravity variable from the My Blueprint panel over to the NewGravity input on the Event Graph
• Compile and Save the Blueprint

Testing the Blueprint

• Hit the drop down arrow on the Play button and select "Advanced Settings"
• In the "Server Game Options" edit box of the "Multiplayer Options" section, enter

  ?mutator=/Game/RestrictedAssets/Blueprints/Mutator_LowGrav.Mutator_LowGrav_C
  

  • The path needs to match the folder that you placed the blueprint in, I've used the place where the shipped example blueprint lives
• Hit the play button and you should now have reduced gravity
  • If you do not, examine the output logs to verify that the mutator loaded successfully. You may see a warning like "LogUObjectGlobals:Warning: Failed to find object 'Class /Game/WrongPath/Mutator_LowGrav_C'", in that case double check the path that you entered in the "Server Game Options"