For me the following worked out:
// Make the line xray
mat.getAdditionalRenderState().setDepthWrite(false);
mat.getAdditionalRenderState().setDepthTest(false);
geom.setQueueBucket(Bucket.Transparent);
For me the following worked out:
// Make the line xray
mat.getAdditionalRenderState().setDepthWrite(false);
mat.getAdditionalRenderState().setDepthTest(false);
geom.setQueueBucket(Bucket.Transparent);