A method for prototyping 3D particle effects within Open GL with the use of configuration files. Config files are in JSON format and can be used to quickly create and modify particle behavior as well as easily export your particle parameters once testing is complete.
The config file is made up of a number of different properties which both affect the particles as well as the emitters of these particles. Once this JSON file is created, it can be added into the project, and the JSON filename can be added to the resourceNames array found in GameViewController.m which will allow viewing from within the app.
Once this JSON file is added to the project, it can be selected and viewed from within the app. When the app is open, tapping the screen will create an emitter at the touch location and show the particle effect in Open GL 3D space.
3D particle effects:
Accompanying JSON file:
{
"birthRate": 4000,
"maximumParticles": 400,
"imageName": "spark.png",
"lifetime": 5,
"lifetimeRange": 0,
"emitterLifetime": 10,
"positionRangeX": 0.02,
"positionRangeY": 0.02,
"positionRangeZ": 0.02,
"positionRadius": 0,
"positionRadiusRange": 0,
"positionTheta": 0,
"positionThetaRange": 0,
"positionPhi": 0,
"positionPhiRange": 0,
"forcePositionOffsetX": 0,
"forcePositionOffsetY": 0,
"forcePositionOffsetZ": 0,
"forceValue": 0,
"isPositionRectangular": 1,
"isPositionRadial": 0,
"isForcePresent": 0,
"angle": 90,
"angleRange": 180,
"phi": 90,
"phiRange": 90,
"speed": 4,
"speedRange": 0.5,
"accelerationX": 0,
"accelerationY": 0,
"accelerationZ": 0,
"alpha": -1,
"alphaRange": 0,
"alphaSpeed": 0,
"alphaCutoff": 0.5,
"scale": 0.8,
"scaleRange": 0.1,
"scaleSpeed": 0,
"perspectiveMaxDistance": 20,
"rotation": 0,
"rotationRange": 0,
"rotationSpeed": 0,
"emitterRotationX": 0,
"emitterRotationY": 0,
"emitterRotationZ": 0,
"emitterRotationSpeedX": 0,
"emitterRotationSpeedY": 0,
"emitterRotationSpeedZ": 0,
"colorR": 0,
"colorG": 0.804,
"colorB": 1,
"colorEndR": 0,
"colorEndG": 0.408,
"colorEndB": 0.894,
"colorRangeR": 0.3,
"colorRangeG": 0.05,
"colorRangeB": 0.2,
}
3D particle effects around a slot machine game prototype:
