I made a very simple animation consisting of two bones flipping their scale in order to achieve a 'flapping' effect. It's a very placeholder animation, but once I brought it into Unity for testing, I noticed an issue that I believe might be problematic if I ever use negative scale in any final animations. Simply put, those quads aren't rendering while their scale is negative. As soon as the animation puts the scale > 0, they show up again.
I am not sure if it's a material issue (I followed the tutorial in the video section http://www.youtube.com/watch?v=x1umSQulghA ) or whether the sub-quads created in the SpineSkeletonAnimation need to be double-sided.
I am using latest Spine 1.6.42, Unity 4.3.1f, with the runtimes from the Dec 6th commit, [5ef80af].
This is the animation json output:
"fly_flap": {
"bones": {
"bn_right_wing": {
"rotate": [
{ "time": 0, "angle": 2.15 },
{ "time": 1.3333, "angle": 75.55 },
{ "time": 2.6666, "angle": 2.15 }
],
"translate": [
{ "time": 0, "x": -0.73, "y": 1.69 },
{ "time": 1.3333, "x": -25.8, "y": 59.34 },
{ "time": 2.6666, "x": -0.73, "y": 1.69 }
],
"scale": [
{ "time": 0, "x": 1, "y": -0.609 },
{ "time": 1.3333, "x": 1, "y": 0.55 },
{ "time": 2.6666, "x": 1, "y": -0.609 }
]
},
"bn_left_wing": {
"rotate": [
{ "time": 0, "angle": 0, "curve": "stepped" },
{ "time": 2.6666, "angle": 0 }
],
"translate": [
{ "time": 0, "x": -0.29, "y": 1.02 },
{ "time": 1.3333, "x": -10.18, "y": 35.82 },
{ "time": 2.6666, "x": -0.29, "y": 1.02 }
],
"scale": [
{ "time": 0, "x": 0.964, "y": 1 },
{ "time": 1.3333, "x": -0.238, "y": 1 },
{ "time": 2.6666, "x": 0.964, "y": 1 }
]
},
"bn_main": {
"rotate": [
{ "time": 0, "angle": -0.28 },
{ "time": 1.3333, "angle": -9.98 },
{ "time": 2.6666, "angle": -0.28 }
],
"translate": [
{ "time": 0, "x": 0.63, "y": 0.7 },
{ "time": 1.3333, "x": 22.28, "y": 24.76 },
{ "time": 2.6666, "x": 0.63, "y": 0.7 }
],
"scale": [
{ "time": 0, "x": 1, "y": 1, "curve": "stepped" },
{ "time": 2.6666, "x": 1, "y": 1 }
]
}
},