Room: Here you can choose the kind of setting that will be used to render the Thea material preview.
Size: This option refers to the pixel resolution of the preview, both for the horizontal and the vertical dimensions.
Quality: The Quality value determines the number of passes that will be used during the rendering of the preview.
Auto Refresh: When the Auto Refresh checkbox is ticked, a change in a Substance™ texture will trigger a regeneration of the material preview usin g the latest version of that texture. If the checkbox is not ticked you will have to manually update the preview using the Refresh button.
As explained in the start of this document, the Thea material is created in a physically-based manner if a Metal/Roughness structure is present in the Substance™ file. To that purpose, four different maps are essential and must be specified: Basecolor, Normal, Roughness and Metallic.
Metallic/Roughness maps only: When this checkbox is ticked, each one of the four texture slots is automatically linked to the texture with the appropriate identifier (for the Base Color texture slot the texture with the basecolor identifier is chosen, etc.). If no appropriate texture is found the slot remains empty and no other textures can be assigned. When the checkbox is not ticked, any texture can be assigned to any slot.
In the Advanced Maps section you can specify additional textures supported by the Thea material system. Specifically, you can assign a Bump texture (which will replace any texture assigned to the Normal slot), an alpha texture which is used for alpha clipping and an emitter texture. When the Passive Emitter checkbox is ticked the emitter does not cast any light but only appears emitting light.
If you have assigned the height map to Displacement in the Advanced Mats rollout, you can use these options to fine tune the displacement of the Thea Material.
Subdivision: Using higher values, the engine will subdivide the geometry on render time making displacement look more detailed.
Height: This value controls the maximum surface displacement in conjunction with the height map.
Center: This value will offset the displaced surface based on the defined value.
Normal Smoothing: Normal smoothing should be turned off when the original surface has sharp edges.
Tight Bounds: LEaving this option enabled will make the engine render faster but initialization will last longer.
Power: Defines the overall power of the emitter using the defines units.
Efficacy: This value defines the energy loss with 683 lm/W corresponding to lights with no energy loss.
IES File: Enable this option to load an IES file.
Multiplier: Use this value to define the power of the IES file.
Passive Emitter: an emitter will not cast light into the scene; but one will be able to still see the area emitter "lit".
Click on the Save button to export the Substance file as a Thea Material (.mat.thea, .mat.pack)