WebGLRenderer: Use object.isSkinnedMesh instead of material.skinning. See #10754.

src/renderers/WebGLRenderer.js

@@ -1828,7 +1828,7 @@ function WebGLRenderer( parameters ) {
 				material.isMeshBasicMaterial ||
 				material.isMeshStandardMaterial ||
 				material.isShaderMaterial ||
-				material.skinning ) {
+				object.isSkinnedMesh ) {
 
 				p_uniforms.setValue( _gl, 'viewMatrix', camera.matrixWorldInverse );
 
@@ -1843,7 +1843,7 @@ function WebGLRenderer( parameters ) {
 		// auto-setting of texture unit for bone texture must go before other textures
 		// not sure why, but otherwise weird things happen
 
-		if ( material.skinning ) {
+		if ( object.isSkinnedMesh ) {
 
 			p_uniforms.setOptional( _gl, object, 'bindMatrix' );
 			p_uniforms.setOptional( _gl, object, 'bindMatrixInverse' );

src/renderers/webgl/WebGLPrograms.js

@@ -57,7 +57,7 @@ function WebGLPrograms( renderer, capabilities ) {
 
 			var maxBones = nVertexMatrices;
 
-			if ( object !== undefined && (object && object.isSkinnedMesh) ) {
+			if ( object && object.isSkinnedMesh ) {
 
 				maxBones = Math.min( object.skeleton.bones.length, maxBones );
 
@@ -169,7 +169,7 @@ function WebGLPrograms( renderer, capabilities ) {
 			sizeAttenuation: material.sizeAttenuation,
 			logarithmicDepthBuffer: capabilities.logarithmicDepthBuffer,
 
-			skinning: material.skinning,
+			skinning: ( object && object.isSkinnedMesh ),
 			maxBones: maxBones,
 			useVertexTexture: capabilities.floatVertexTextures && object && object.skeleton && object.skeleton.useVertexTexture,