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Light Function Problem

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    Light Function Problem

    I'm trying to set up a light with a Light Function, following one of Hourences tutorials.

    Now, I can't seem to add my material to the Light Function. When I click on the blue arrow, nothing happens. Hovering my mouse over the Function box, a pop up says that in order to use Light Functions, I have to set UseDirectLightMap=False.

    Okay, I'm down with that. Except: There is no UseDirectLightMap for me to set to false!. Every tutorial and documentation that I look at shows this to be under the LightComponent part of the Lights properties, but it's not there for me (which by the way, my properties boxes always seem to look different than those in the documents or any tutorials. I'm using the latest version of the UDK.

    I've tried this with Point, Spot and Directional lights, and none of them have the UseDirectLightMap in them.

    Could someone please tell me where it's at, or what I have to do to get this set correctly?

    Please try following the UDN document on Light Functions as it is more up to date than Hourences one.


    I imagine the chief problem is that the light type you selected was not dynamic.


      Thanks, changing it to a Movable light did the trick. I have read through the document you linked, and others, but no where can I find where it says that lights must be dynamic that I see. Only that you can use it with Point, Spot and Directional. Here is a quote from the overview for Light Functions from the document you linked:

      Lights functions are mathematical representations of how lights should illuminate the scene in Unreal Engine 3. By default, lights will use a constant value based on the various inputs defined by the light component; such as brightness and color. Light functions allow you to define more interesting set ups to achieve flicking lights, masked lights and strobing lights, textured lights. Light functions use the material system in Unreal Engine 3, making it really easy for artist and level designers to create and modify. Also, because light functions uses the material system, these light functions can be instanced for variations.


        What type of lights can be used?
        The only light type that isn't supported are sky lights, however this makes sense since sky lights simply define the ambient light everywhere. Lights can be any these variations; dominant, movable or toggle-able and may cast dynamic shadows if desired. Light functions can no longer be created for static lights; Unreal Editor will fail to create the light function if an inappropriate light was selected.
        It says it in the document, under its own paragraph no doubt.


          DOH! You're right! I missed that! Time to get new glasses.