Before you start working on your mesh, make sure Blender’s scene units are set up correctly. To do so, switch to the Scene tab in the Properties menu and choose either the Inches preset or set the length to None.
Mesh scale and orientation
We’ll use the default Suzanne monkey head as an example prop for this tutorial. Add it to you scene by pressing Shift+A → Mesh → Monkey. You can check the size by opening the 3D viewport’s right menu by pressing N and taking a look at the dimensions in the Transform category. For this tutorial we’ll scale up Suzanne until the Z size is roughly 6.5 feet or 78 inch/generic units. To do so, press S and move your cursor away from the monkey head to scale it up. Confirm with the left mouse button.
Apply the mesh’s scaling by pressing Ctrl+A → Rotation and Scale. Make a habit of always applying scaling and rotation before exporting a mesh to Hammer.
Your mesh should be facing south in Blender to be aligned properly with Hammer's coordinates, which the monkey head does by default.
Open the 3D viewport’s left menu with T and click Smooth to change Suzanne to smooth shading.
Adding two materials
First, switch your renderer to Cycles in Blender’s header. This is not needed to create materials - however, as the Blender Renderer will be discontinued in the future and has been removed from Blender 2.8 you should switch it to Cycles, so you can continue working on old props seamlessly when updating to the new Blender version.
We will create two different materials, a red and a blue one. Navigate to the Material tab in the Properties and click on New to create a new material.
Click on the + icon to create a new empty material slot. Select this slot and press the big new button again to create a second material. Rename the materials to red and blue.
The material name you enter here is not relevant or tied to the material name used by Hammer. But for the sake of consistency it is advised to use the same material name as in the engine.
Hammer can’t read the materials unless you add a so called Custom Property to them that points to the correct material name and path used in Hammer.
Select the red material. For this tutorial we’re going to assume that you have created a material called red.vmt in the folder “materials/models/props_items” of your project with Hammer’s material editor.
There’s a Custom Properties category in the material menu. If you can’t see the big Add button in it, click the Custom Properties text to expand it. Make sure your red material is selected and click the Add button. A new property with the Property Name prop and Property Value of 1 will be created. Click the Edit button and change the name to FBX_vmatPath and the value to materials/models/props_items/red.
Repeat the same steps for the blue material, but change the value to materials/models/props_items/blue.
Choose a Viewport Color in the Settings category of both materials. Switch to Edit Mode by pressing Tab and assign the two materials to different faces by using the Assign button in the material editor.
Click on File → Export → FBX to export you mesh as FBX. For this tutorial we’ll assume that you project has a models\props_items\fbx\ folder.
|Selected Objects||Tick this box if your scene contains more than one prop. Make sure to select the right prop before opening the export dialogue.|
|Apply Scalings||Choose FBX All.|
|Forward / Up||This does not seem to affect the mesh’s orientation in Hammer. For the sake of consistency with Hammer’s coordination system it’s set to X Forward and Z Up.|
|Custom Properties||Make sure to tick this box or your materials will not be recognized in Hammer.|
You can safely ignore the tabs Geometries, Armatures and Animation for regular props. Enter a prop name in the upper toolbar and click on Export FBX in the upper right to export your mesh.
If you'd like to save your settings as a preset, click on the + button to the right side of the Operator Presets list and enter a name. You can select the new preset by clicking on the Operator Presets button. Remember to always select the preset before exporting in a new Blender session, as the selected preset is reset when Blender is closed.