Blender Gamekit Lua Constrain Plane Side Movement

Blender 3D game engine provides location constraint to limit object in a certain area. However this was not implemented in the Gamekit package. I have to do some scripting to get around it. So my plane will not fly out of the screen. Below is the script and red bits are my explanations. This is apart of series tutorials to create a 2d arcade plane game using Blender 3D and gamekit. Check this blog for more details.

-------BELOW IS OnInit.lua--------------

--Global variable

    --set touch move parameters

    Sensitivity = 0.005

    --invert = -1 -> is inverted

    Invert = 1

    Threshold=3.5

 -- Plane Constrain parameter

    Xmin = -0.87 --This is the left boundary, adjust if necessary

    Xmax = 0.87 --This is the right boundary, adjust if necessary

--this function is to stop plane moving cross the boundary

function xMoveFilter(limitSignal,oldX)

    if limitSignal == -1 and oldX > 0 then

        return oldX

    elseif limitSignal == -1 and oldX < 0 then

        return 0

    elseif limitSignal == 1 and oldX >0 then

        return 0

    elseif limitSignal ==1 and oldX <0 then

        return oldX

    end

        return 0

end

--this function is to determine whether plane is over the broundary

function XoverLimit(obj)

    local vec3 = obj:getPosition()

    if vec3.x < Xmin then

        return -1

    elseif vec3.x > Xmax then

        return 1

    else

        return 0

    end

end

--this function is for debug used to display plane position

function printPosition(obj)

    local vec3 = obj:getPosition()

    dPrintf("position x: " .. vec3.x)

    dPrintf("position y: " .. vec3.y)

    dPrintf("position z: " .. vec3.z)

    

end    

function velocityCap(v,vmax)

    if (v>vmax) then

        return vmax

    elseif (v < -vmax) then

        return -vmax

    else return v

    end

end

-------BELOW IS planeTouchMove.lua--------------

mouse=OgreKit.Mouse()
scene = OgreKit.getActiveScene()
play = scene:getObject("plane")
logicM = OgreKit.LogicManager()
myLogicObject = logicM:getObject("plane")
mySensor = myLogicObject:getSensor("Collision")
maxVelocity=0.08

mouse:capture()

--print current plane posistion on screen

printPosition(play)

--using threshold to filter out unwanted small touch movement

if ((mouse.xrel>Threshold or mouse.xrel<-Threshold)or(mouse.yrel>Threshold or mouse.yrel<-Threshold)and (not(play.touchBoundary))) then
      velocityY=velocityCap((mouse.yrel) * Sensitivity, maxVelocity)
      velocityX=velocityCap((mouse.xrel) * Sensitivity, maxVelocity)

      --check if plane over screen boundary 

      limitSignal = XoverLimit(play)

      --the X Y directions are swapped as the screen is in landscape

      if limitSignal==0  then

      --when plane is inside boundary

        play:translate(-velocityY* Invert,-velocityX * Invert,0)
      else

      --when plane touches boundary it can only move away from boundrary

        newY = xMoveFilter(limitSignal,-velocityY * Invert)
        play:translate(newY,-velocityX * Invert,0)
      end
end

    

Blender 3D Gamekit Plane Shoot Bullet IOS Android Tutorial

This is a follow up to the plane arcade game tutorial posted before. This time I added plane shooting bullet. For how to run it on real android device such as nexus 7, and ios devices, such as iPad. Please go to my youtube channel: http://www.youtube.com/user/hhhnzw. there are videos showing that.

1. if you continue from last tutorial first thing is to rename the Background image from Plane to background. it is confusing, as the aeroplane is also called plan.

2. Create an empty element. set its parent to plane. and move it to centre of the plane. and move down. so the Z axis' number is -0.1. Rename it as EmptyGunCentre.

3. Create a box, and scale smaller, it will become bullet. So pick a size as you think is proper. Rename it to bullet01.
4. Unwrap & export UV map from the box. and paint it to look like a bullet.
5.load the edited uv map in blender, and apply it to bullet element.
6. Put bullet on to layer 2, HIDDEN layer.
7. Pick the EmptyGunCentre, go to game logic editor to set it up like image below:

8. Turn on the hidden layer and pick the bullet. Then go to physics tab. Change type to dynamic. Change the min max velocity to 3.5. And lock Z axis.

9. Now pack the content in, and save the file. Test it on PC first. Then follow my other videos to run it on Android and IOS devices.

Blender file can be downloaded from link below:

https://docs.google.com/file/d/0B2dWucciRgDPZDNGMlBROW9sekE/edit?usp=sharing

Blender 3d Gamekit Touch Move Android Tutorial

Following last tutorial, background moving, as moving direction is wrong, we need to fix it first.
1. Rotate camera and change motion direction in game logic editor.
2. Adjust plane shape.
3. Cut seam line on the plane model. And generate uv map.
4. Export uv map as image file.
5. Open uv map in gimp2 to paint the texture.
6. Save image and load into Blender
7. Apply texture to plane. And verify in 3d view.
8. Creat txt file. Name it OnInit.lua and put some global variables/parameters. So later on if we want to change something globally, we can easily find them. This script will be called automatically when game starts.

--Global variable

    --set touch move parameters

    Sensitivity = 0.005

    --invert = -1 -> is inverted

    Invert = 1

    Threshold=3.5

9. Create txt file called planeTouchMove.lua and put following code......

mouse=OgreKit.Mouse()

scene = OgreKit.getActiveScene()

play = scene:getObject("plane")

mouse:capture()

--display mouse movement for debug

--dPrintf("---xrel: " .. mouse.xrel)

--dPrintf("---yrel: " .. mouse.yrel)

--dPrintf("---xrel + yrel: " .. mouse.xrel+mouse.yrel)

--using threshold to filter out unwanted small touch movement

if ((mouse.xrel>Threshold or mouse.xrel<-Threshold)or(mouse.yrel>Threshold or mouse.yrel<-Threshold)) then

      play:translate(-(mouse.yrel) * Sensitivity * Invert,-(mouse.xrel) * Sensitivity * Invert,0)

      dPrintf("---xrel: " .. mouse.xrel)

      dPrintf("---yrel: " .. mouse.yrel)

else

     dPrintf("no movement")

     

end

What does this do is measuring mouse movement. And pass it to the plane. It uses sensitivity and invert variables defined in the onInit.lua file to adjust the movement. And use threshold to filter out unwanted tiny figure movement.

10. Go to plane game logic and create sensor mouse + movement and click the positive pulse "..." button, it is the first to the left.

11. In game logic link sensor with lua script.
12. Pack content and save file.
13. Test on desktop.
14. Copy the blender file into android project asset folder.
15. Open eclipse and android Gamekit file.
16. Refresh asset folder and goto main.java to change file name to the one just copied.
17. Connect android device to desktop
18. In eclipse save and run.

blender file is available at:https://docs.google.com/file/d/0B2dWucciRgDPUmFOc19ibFNYNmc/edit?usp=sharing

How to do Background Rolling On Mobile Device Using Blender & Gamekit

This demo showing how to create a rolling background as seen on arcade platform 2D/2.5D games using blender3D and gamekit. at the end test on a real android device Nexus 7.
Following are the Steps:
1. Create a 'mesh plane' rectangular as background
2. Move and Rotate Camera
3. Import pre-modelled Plane
4. Add shadeless material to background
5. Unwrap UV,1024 x 1024
6. export UV image
7. stitch background image on UV map in photoshop or gimp2
8. save the image
9. load image into texture under material
10. add game logic to camera and airplane
11. pack external data in file and save file
12. test on blender gamekit add-on using desktop
13. copy file into gamekit android package asset folder
14.open eclipse, change the file name reference in the main.java file
15. connect nexus 7 and run the test.

the blender file can be download at

https://docs.google.com/file/d/0B2dWucciRgDPLXVvQjJYZk13T2c/edit?usp=sharing

ios 3D game Test on Simulator

  

ios game 'switch' using Blender 3D 2.6 and gamekit game engine
build iOS iPhone ipad game using free Blender 3D and GameKit,
Just a little programming knowledge required.

Game Engine iOS Build Tutorial

this video showing how to build blender 3d gamekit ( free game engine )iPhone ios application for running blender 3D game on iOS devices.
download cmake from cmake.org.in xcode project setting, change code signing to no, i missed that in the video.

The goal of gamekit is to create a basic game engine that allows fast prototyping build around open source software free for commercial use.

Using Ogre or Irrlicht for graphics, Bullet for physics, OpenAL for sound
OgreKit is most actively developed and in svn/trunk, the suspended Irrlicht version is in svn/branches/IrrKit.
Engine is written in C++ and the game logic can be done in C++, Lua scripting or logic bricks

Android Switch & Car Rotate Demo Source

As there are several request in youtube for source code and tutorial, here i put the android game-kit and blender3d file for download.

http://pan.baidu.com/share/link?shareid=178299&uk=1259096542
another link
https://docs.google.com/file/d/0B2dWucciRgDPNGQtcnpuaGtZaE0/edit?usp=sharing
link for car rotation blender file
https://docs.google.com/file/d/0B2dWucciRgDPZmZucEpiR1Y2RGc/edit?usp=sharing

Android openGL touch look testing on nexus 7

Blender 3D gamekit Android opengl touch look testing on nexus 7 

using Lua Script to build game logic

below is the lua script used in video:

Sensitivity = 0.005

Invert = 1

Threshold=6

--OgreKit.DebugPrint(Sensitivity)

mouse=OgreKit.Mouse()

scene = OgreKit.getActiveScene()

play = scene:getObject("Player")

sensor=scene:getObject("senMouseLook")

mouse:capture()

--dPrintf("---xrel: " .. mouse.xrel)

--dPrintf("---yrel: " .. mouse.yrel)

if mouse.xrel+mouse.yrel>Threshold or mouse.xrel+mouse.yrel<-Threshold then

    play:roll( -(mouse.xrel ) * Sensitivity * Invert,OgreKit.TS_LOCAL)

    play:pitch( -(mouse.yrel) * Sensitivity * Invert,OgreKit.TS_LOCAL)       

end