Displacement mapping utilizes a 2D texture map in order to generate 3D surface relief. As opposed to bump and normal mapping, Displacement mapping does not only provide the illusion of depth but it effectively displaces the position of points over the
Surface based on light and dark values of the Displacement texture.
The displaced surface should have UV texture coordinates and only image textures will work. Procedural textures such as Octane Turbulence will not work.
The Octane Displacement node controls how the surface is displaced by the texture. To use a displacement map first connect the Octane Displacement node to the Displacement slot on the Octane shader, then connect the Image Texture to the Texture slot on the Displacement node (figure 1).
Figure 1 : A Displacement node is connected to an Octane shader in the Hypershade
Determines the strength or effect of the displacement texture (see Figure 2).
Figure 2 : A diagram illustrating how the Height parameter calculates displacement.
Defines the shift of the displacement in texture value range. This value should be set to 0.5 for image textures that use 50% to represent no displacement. This value should be set to 0 for images, such as 32 bit EXRs, that use black to represent no displacement. If a digital sculpting program such as ZBrush is used to generate the displacement the best results are achieved by setting the Mid value to 0.5 in ZBrush when the displacement texture is generated and then setting the Mid value of the Octane Displacement node top 0.5 as well.
This slot provides the path to the displacement map texture. Displacement maps are image textures typically generated in content creation software such as ZBrush, 3D Coat, Substance Designer or Photoshop.
Level of details
Adjust the quality of details in the map. Higher values can help reduce artifacts seen in shadows cast on the displaced surface and bring out finer details in the surface but may increase render time. Figure 3 shows a displaced surface with different Levels of details settings.
Figure 3 : A comparison of renders of a displaced surface with different Levels of details settings.
Displacement map Limitations:
Octane displacement supports only Octane Image Textures. Procedural textures such as Octane Turbulence will not work.
Calculating displacement geometry places additional load to the GPU which can increase render times.
Very high or extremely low Height values may cause artifacts as well as and GPU errors.
Artifacts may appear on displaced surfaces in large scale scenes. This may be fixed by adjusting the Scale Units setting in the Additional section of the OctaneRender Settings tab of the Render Settings window.
Displacement mapping is best used for emphasis of small to medium size details inherent in the textural aspects of the surface rather than major features that can be provided by the shape of the geometry. For example displacement works well for cracks in a rocky terrain but should not be relied upon entirely for creating the shape of the terrain itself.
Currently, Octane Displacement cannot be used together with a normal map as part of the same material as this would result in rendering artifacts on surface.
There is a workaround: You can use a Mix material to combine two materials that have textures applied to their Bump/Normal channels, and apply displacement to the Displacement channel of the Mix Material itself.