Once a 3D model has transcoded open Modest3D to start making your 3D interactive scenario.
Modest3D defaults to include a Begin Node and a Setup Node. All changes to the layout of your scene are completed through the setup node. You should see the items that you have loaded to your project in the assets tab.
Click on the Setup node.
Click on the model you want to load in the 3D scene and drag it to the setup node.
Double click the setup node and the 3D model will be shown as "ModelName (SceneModel)" to show that this has now been added to the scene.
Click "Simulate" and the model will appear in the 3D scene.
Note: See the setup node documentation next. There is lots of useful functionality in setup node.