attempt to compare nil with number [SOLVED]

[Guinner]

So whenever i'm running my code i'm getting this:

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[+ Warning ] {Scripting         }---------------------------------------------------------------
[+ Warning ] {Scripting         }AI Runtime error : [Handler] EnemyTestAI.onEnterFrame (line 30): attempt to compare nil with number
[+ Warning ] {Scripting         }---------------------------------------------------------------
[+ Warning ] {Scripting         }AI Stack Traceback :
[+ Warning ] {Scripting         }    [Line  30] : Handler 'onEnterFrame'
[+ Warning ] {Scripting         }---------------------------------------------------------------

I did some research and the main problem behind this usually is not declaring the variable. But I have this under enterframe:

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if (hVariable < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end

And this under onInit:

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application.setCurrentUserEnvironmentVariable ( "health", "100" )

So I know i've declared it.
What could be going on?

[dtr1au]

Hi Guinner,

Did you try remove the quotes around the value for health when setting it?

So instead of:
application.setCurrentUserEnvironmentVariable ( "health", "100" )

Use:
application.setCurrentUserEnvironmentVariable ( "health", 100 )


With the quotes the variable type becomes a string, you probably want it to be a number, remove the quotes and it will be that. It may mess up other areas of you game though if you've built other things that depend on health being a string. You will need to convert the data type to either a string or number wherever you need it. Look at all the string functions in the documentation to determine what you want to do.

Hope that helps.

[Guinner]

Hey dtr1au,
Thanks for the quick reply, however that hasn't seemed to fix the problem. It is still the same error.

[dtr1au]

Can you post how hVariable is being declared?

[Guinner]

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local hVariable = application.getCurrentUserAIVariable ("EnemyTestAI", "health" )

[neilb]

You appear to be setting an environment variable called Health, then retrieving the value from an AI variable also called Health which wouldn't have been initialised.

You'd want to set the variable using application.setCurrentUserAIVariable

[Guinner]

Code: Select all

local hVariable = application.setCurrentUserEnvironmentVariable ( "health", 100 )


if (hVariable < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end

So i've set it up like so, with still no success. Same error :/

[neilb]

Use getCurrentUserEnvironmentVariable to read the value, you've got setCurrentUserEnvironmentVariable in the code you pasted.

[Guinner]

OnInit:

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application.setCurrentUserAIVariable ( "EnemyTestAI", "health", 100)

OnEnterFrame:

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local vValue = application.getCurrentUserAIVariable ( "EnemyTestAI", "health" )

if (vValue < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end
----------

And i've created it in the explorer as a number. Still no bingo.

[neilb]

Is EnemyTestAI added as a main AI to the project - ie. not as a resource, but an AI in the main AI's list?

Have you tried stepping through the code to confirm that the onInit code is actually being called before the onEnterFrame?

[broozar]

wrong parameter count.

OnInit:

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application.setCurrentUserEnvironmentVariable ( "health", 100)

not ( "EnemyTestAI", "health", 100). the function is designed to take 2 parameters (name and value), not 3.

OnEnterFrame:

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local vValue = application.getCurrentUserEnvironmentVariable ( "health" )
--and not ( "EnemyTestAI", "health" ). this function takes only 1 parameter (the var name), nothing more.

if (vValue < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end
----------

it's all in the manual.
http://www.stonetrip.com/developer/doc/api/application-setCurrentUserEnvironmentVariable
http://www.stonetrip.com/developer/doc/api/application-getCurrentUserEnvironmentVariable

[Guinner]

Thank you - I was getting confused between AIVariable and EnvironmentVariable.
I'm not at my computer right now, but i'll try this when I get home and let you know how it goes.
Thanks.

[Guinner]

wrong parameter count.

OnInit:

Code: Select all

application.setCurrentUserAIVariable ( "health", 100)

not ( "EnemyTestAI", "health", 100). the function is designed to take 2 parameters (name and value), not 3.

OnEnterFrame:

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local vValue = application.getCurrentUserAIVariable ( "health" )
--and not ( "EnemyTestAI", "health" ). this function takes only 1 parameter (the var name), nothing more.

if (vValue < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end
----------

it's all in the manual.
http://www.stonetrip.com/developer/doc/api/application-setCurrentUserEnvironmentVariable
http://www.stonetrip.com/developer/doc/api/application-getCurrentUserEnvironmentVariable/quote

That's the argumentcount for EnvironmentVariable sorry? Im using AI variable?
Now i'm getting wrong argument count errors?

[broozar]

oh crud. sorry. of course i meant "...EnvironmentVariable". corrected in the post above.

---------------------

your "...CurrentUserAIVariable" code does not work because EnemyAI is not part of the current user AIs, but an object AI. to make it work, use the object API. http://www.stonetrip.com/developer/doc/api/object-setAIVariable

[Guinner]

Thank you,
this is now solved: For reference of anyone searching for the same problem my end code was

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--------------------------------------------------------------------------------
--  Handler.......... : onEnterFrame
--  Author........... :
--  Description...... :
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
function EnemyTestAI.onEnterFrame (  )
--------------------------------------------------------------------------------
local hUser = application.getCurrentUser ( )
local hComponent = hud.getComponent ( hUser, "myHUD.myComponent" )   
local hObject = (this.getObject ( ))
local hCamera = scene.getTaggedObject (application.getCurrentUserScene(), "ProperCamera")
--The scene 3D coordinates of the object
local sceneX, sceneY, sceneZ = object.getTranslation ( hObject, object.kGlobalSpace )

--Screen coordinates (-1,1)
local hudX, hudY = camera.projectPoint ( hCamera, sceneX, sceneY + 1, sceneZ )

--Convert to HUD coordinates (0,100)
hudX = hudX * 50 + 50
hudY = hudY * 50 + 50

--Place the component
hud.setComponentPosition (hComponent, hudX, hudY )

local vValue = object.getAIVariable (hObject, "EnemyTestAI", "health" )

if (vValue < 0) then
hud.setLabelText ( hComponent, "DEAD!")
end
--------------------------------------------------------------------------------
end
--------------------------------------------------------------------------------


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--------------------------------------------------------------------------------
--  Handler.......... : onInit
--  Author........... :
--  Description...... :
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
function EnemyTestAI.onInit (  )
--------------------------------------------------------------------------------
    local hUser = application.getCurrentUser ( )
hud.newTemplateInstance (application.getCurrentUser ( ), "HUD_GAME", "EnemyTest" )
hud.newTemplateInstance ( hUser, "myHUD", "myHUD"  )
--application.setCurrentUserAIVariable ( "health", 100)
local hObject = (this.getObject ( ))
object.setAIVariable ( hObject, "EnemyTestAI", "health", 100 )
--------------------------------------------------------------------------------
end
--------------------------------------------------------------------------------