}
private void fillVerticesGPU (int[] particlesOffset) {
int tp=0;
for(BillboardControllerRenderData data : renderData){
FloatChannel scaleChannel = data.scaleChannel;
FloatChannel regionChannel = data.regionChannel;
FloatChannel positionChannel = data.positionChannel;
FloatChannel colorChannel = data.colorChannel;
FloatChannel rotationChannel = data.rotationChannel;
for(int p=0, c = data.controller.particles.size; p < c; ++p, ++tp){
int baseOffset = particlesOffset[tp]*currentVertexSize*4;
float scale = scaleChannel.data[p* scaleChannel.strideSize];
int regionOffset = p*regionChannel.strideSize;
int positionOffset = p*positionChannel.strideSize;