MaterialDef does not extend AssetKey

Benoit_Dubreuil · May 21, 2018, 4:09pm

Is there a reason why the MaterialDef class does not extends from AssetKey?

I understand that material definitions are actually loaded by materials themselves but is it actually possible to load a material definition from a piece code?

The reason I’m asking this is because I’m making a meta-asset project that generates code for all assets, including their asset keys.

EDIT : Whilst searching for .vert and .frag asset keys, I found out that the class ShaderNodeDefinition, which extends AssetKey, is for material definitions. Am I correct? It’s quite ambiguous if I should use the ShaderNodeDefinition or MaterialDef class.

I am quite confused myself by all the asset types, so sorry if say something wrong.

nehon · May 25, 2018, 1:43pm

The reason is, there is absolutely no reason to do it.
The AsseyKey class is used to send loading params to the assetManager (and to the undelying asset loader) to load an asset. The MaterialDefinition is an asset.

Mhh somehow, the material definitions is needed to load the material yes, and there are convenience methods to create a material loading the materialDef.

Any JME asset can be loaded with assetManager.loadAsset(“path/to/asset”) with an optional assetKey. loadModel, loadMaterial… are convenience methods.

Definitely not. It would make no sense at all

github.com

jMonkeyEngine/jmonkeyengine/blob/master/jme3-core/src/main/java/com/jme3/shader/ShaderNodeDefinition.java#L51


      
          import java.util.ArrayList;

          import java.util.Arrays;

          import java.util.List;

          

          /**

           * Shader node definition structure meant for holding loaded data from a

           * material definition j3md file

           *

           * @author Nehon

           */

          public class ShaderNodeDefinition implements Savable {

          

              private String name;

              private Shader.ShaderType type;

              private List<String> shadersLanguage = new ArrayList<>();

              private List<String> shadersPath = new ArrayList<>();

              private String documentation;

              private List<ShaderNodeVariable> inputs = new ArrayList<>();

              private List<ShaderNodeVariable> outputs = new ArrayList<>();

              private String path = null;

              private boolean noOutput = false;

You must mistake with

github.com

jMonkeyEngine/jmonkeyengine/blob/master/jme3-core/src/main/java/com/jme3/asset/ShaderNodeDefinitionKey.java#L43


      
          
          import com.jme3.asset.cache.AssetCache;
          import com.jme3.shader.ShaderNodeDefinition;
          import java.util.List;
          
          /**
           * Used for loading {@link ShaderNodeDefinition shader nodes definition}
           *
           * Determines whether the definition will be loaded with or without its documentation
           */
          public class ShaderNodeDefinitionKey extends AssetKey<List<ShaderNodeDefinition>> {
          
              private boolean loadDocumentation = false;
          
              /**
               * creates a ShaderNodeDefinitionKey
               *
               * @param name the name of the asset to load
               */
              public ShaderNodeDefinitionKey(String name) {
                  super(name);

Which is the AssetKey to load a ShaderNodeDefinition.

It’s only for material definitions using shader nodes.

What do you want to do exactly, because that :

Is really ambiguous to me.

Benoit_Dubreuil · May 25, 2018, 2:21pm

Basically, I just want to know what is the AssetKey class for a material definition.

I generate code (enums) for each assets, their hierarchies and now I was a adding a new piece of code to generate each asset’s key.

nehon · May 25, 2018, 6:03pm

There is no specific key for MaterialDef class, if you need a key you can use new AssetKey<MaterialDef>().

normen · May 26, 2018, 9:58pm

An assets key is equivalent to it’s path, it’s the bit most people don’t understand about the asset system. (“Why can’t I move files” “Why can’t I use j3o as an exchange file format” etc)