Revert "Material: Remove obsolete callbacks. (mrdoob#28702)"

This reverts commit 5557d53.

Author: hybridherbst

src/materials/Material.js

@@ -501,6 +501,10 @@ class Material extends EventDispatcher {
 
 	}
 
+	onBuild( /* shaderobject, renderer */ ) {}
+
+	// onBeforeRender and onBeforeCompile only supported in WebGLRenderer
+
 	/**
 	 * An optional callback that is executed immediately before the material is used to render a 3D object.
 	 *

src/renderers/WebGLRenderer.js

@@ -2081,6 +2081,8 @@ class WebGLRenderer {
 
 				parameters.uniforms = programCache.getUniforms( material );
 
+				material.onBuild( object, parameters, _this );
+
 				material.onBeforeCompile( parameters, _this );
 
 				program = programCache.acquireProgram( parameters, programCacheKey );

src/renderers/common/Renderer.js

@@ -2822,6 +2822,8 @@ class Renderer {
 
 		object.onBeforeRender( this, scene, camera, geometry, material, group );
 
+		material.onBeforeRender( this, scene, camera, geometry, material, group );
+
 		//
 
 		if ( material.allowOverride === true && scene.overrideMaterial !== null ) {