MaterialDef def = (MaterialDef) assetManager.loadAsset(matdefName);
for (TechniqueDef techDef : def.getDefaultTechniques()){
if (techDef.isUsingShaders()){
DefineList dl = new DefineList();
dl.addFrom(techDef.getShaderPresetDefines());
ShaderKey shaderKey = new ShaderKey(techDef.getVertexShaderName(),
techDef.getFragmentShaderName(),
dl,
techDef.getVertexShaderLanguage(),
techDef.getFragmentShaderLanguage());
Shader shader = assetManager.loadShader(shaderKey);