Help needed in fixing character animation

Getting Started Newbie Questions
#81

Hey, Brent, I added a flag just like you said, But I haven’t been having much luck, here are the modifications:

local function checkVelocities() local vx, vy = anim:getLinearVelocity() local stopped = (vx ^2 + vy ^2 \<= 1) local stoppedvy = (vy ^2 \<= 0.5) if stopped == true and anim.sequence ~= "idle" then idle() end if stoppedvy == true then anim.isJumping = false else anim.isJumping = true if anim.sequence ~= "jump" then anim:setSequence("jump") anim:play() end end end local function makeControls(self, event) if event.phase == "began" then if self.name == "left" and anim.isJumping == false then walk(-1) elseif self.name == "right" and anim.isJumping == false then walk(1) end elseif event.phase == "ended" or event.phase == "cancelled" then idle() end return true end&nbsp;

Also, recall, that the jump is now a touch listener on the screen not on a button. 

If I am doing something wrong, can you please say so? (In case, that sounded rude, it’s not, I really appreciate your help) Thank you. Right now the problem is problem #2. I have not tested #1 yet, as I need Live Builds to replicate it. 

#82

I’m still not a big fan of checking velocities. It generally works, but I want to be certain that my approach works. That’s why I prefer the foot sensor method.

I suggest detecting the “ended” collision phase of the foot sensor element instead… meaning when the foot sensor exits (stops) making contact with a solid surface. When it does, set your “isJumping” flag to true. And of course, when the foot sensor begins (“began” phase) collision with a solid surface, set it back to false.

Brent

#83

Ok, but now it only stays at true. 

if ( event.element1 == 2 and event.object2.objType == "ground" ) then if ( event.phase == "began" ) then anim.sensorOverlaps = anim.sensorOverlaps + 1 anim.isJumping = false elseif ( event.phase == "ended" ) then anim.sensorOverlaps = anim.sensorOverlaps - 1 anim.isJumping = true end end
#84

You should only change its state if it’s completely outside of all ground objects. You seem to have the groundwork laid for this (no pun intended) with the “sensorOverlaps” check. Set the other flag to true only if that value is 0, meaning it’s not in contact with any other pieces of ground.

#85

But now it only stays at false. Sensor Overlaps never hits 0, it only hits 1. 

#86

I’d need to see your code…

#87 
local anim = display.newSprite(parent, sheet, sequenceData ) anim.x = 90 anim.y = 0 anim:setSequence("idle") local walkBodyParams = {halfWidth = 30, halfHeight = 50, x = -10, y = 0} physics.addBody(anim, "dynamic", {box = walkBodyParams}, {box = {halfWidth = 20, halfHeight = 10, x = -10, y = 50}, isSensor = true} ) anim:play() anim.isSleepingAllowed = false anim.isFixedRotation = true anim.sensorOverlaps = 1 anim.isJumping = false local function sensorCollide(event) if ( event.element1 == 2 and event.object2.objType == "ground" ) then if ( event.phase == "began" ) then anim.sensorOverlaps = anim.sensorOverlaps + 1 anim.isJumping = false elseif ( event.phase == "ended" ) then anim.sensorOverlaps = anim.sensorOverlaps - 1 end if anim.sensorOverlaps == 0 then anim.isJumping = true end end end

Keep in mind, the character starts out with 1, instead of 0 sensor overlaps as was told in the tutorial on the Corona website.

#88

Code should be more like this… note that I moved the check for “zero overlaps” inside the “ended” condition block:

[lua]

local function sensorCollide(event)

    if ( event.element1 == 2 and event.object2.objType == “ground” ) then

       if ( event.phase == “began” ) then

           anim.sensorOverlaps = anim.sensorOverlaps + 1

           anim.isJumping = false

       elseif ( event.phase == “ended” ) then

           anim.sensorOverlaps = anim.sensorOverlaps - 1

           if anim.sensorOverlaps == 0 then

              anim.isJumping = true

           end

       end

    end

  end

[/lua]

Also, you should not start the “sensorOverlaps” at 1. Always start it at 0 and let the physics engine control that value. If you start it at 1, and then the character begins at some point where the sensor is touching ground, then the value will become 2 because you’re adding +1 to it… and of course that’s wrong, because in truth the sensor is only touching one ground element.

Take care,

Brent

#89

Now it won’t allow me to jump, because the sensorOverlaps value stays at 0, permanently. The character starts off falling in mid-air, and then hits the ground. All of the time, the sensorOverlaps are at 0. (I am printing them out on an enterFrame)

Is this some sort of glitch or am I not detecting the collision right? (it’s probably me)

#90

There’s nothing in the collision code that should be keeping it at 0. Maybe you’re resetting it to 0 at some other place in your code.

#91

I checked my code using a find and replace, it only appears in that function and the jump function:

local function jump(event) if (event.phase == "began" and anim.sensorOverlaps \> 0 and anim.sequence ~= "jump")
#92

I assume you must have set the “sensorOverlaps” property on the character at one point, initially, before the game really gets running…

#93

And where I set it on the character:

 anim.sensorOverlaps = 0

Sorry, forgot about that one.

#94

I don’t mean to digress from this topic (we’ll get back to it), but may I ask why you’re using “global” collision detection for a game that appears to use one primary character that may collide with various enemies, hazards, etc.? Generally, this is the ideal case to use “local” collision detection…

Brent

#95

Oh yeah, I can just combine the other collisions into this function.  :wacko:

#96

Now that it’s local I am seeing some activity, but when I jump this gets printed out:

0 1 2 2 2

Those are the sensorOverlaps…

0, 1 when it goes from ground to air.

2,2,2 when it hits ground.

#97

Did you already change everything into “local” collisions? Note that will change quite a few property names throughout, especially with how you reference things. For example, “event.element1” will become “event.selfElement”, etc.

See here for a comparison:

https://docs.coronalabs.com/api/event/collision/index.html

#98

Yes.

function anim:collision(event) if ( event.selfElement == 2 and event.other.objType == "ground") then if ( event.phase == "began" ) then self.sensorOverlaps = self.sensorOverlaps + 1 self.isJumping = false elseif ( event.phase == "ended" ) then self.sensorOverlaps = self.sensorOverlaps - 1 if self.sensorOverlaps == 0 then self.isJumping = true end end end print(self.sensorOverlaps) end anim:addEventListener("collision")
#99

It appears then you’re getting expected values for “sensorOverlaps” finally. What is the issue at this point?

#100

At this point, it’s still Problem #2, I was having at the top of this post. But, we can leave it for tomorrow. I need a shower. :wacko:  Thanks for the help so far!