Displacement Mapped Objects

A displacement map is a kind of texture map which contains values to offset vertices from a surface along a vector direction.  Each texel in displacement map is a scalar value specifying distance to translate a vertex location from it's surface plane.
Note displacement mapped objects cannot be used in CSG functions

Displacement Map Types

    • Variation - Contains 2 layers, scalar layer values are added together at render time to produce final vertex displacement value
        Layer 1 - Procedural: Auto generated map used for random pattern like displacement surface effects.
        Layer 2 - Interactive: Interactively create vertex displacements on objects using a brush effect
    •
User defined - A texture map used for displacement applied to objects using Window: Textures menu command
        1.  RGB maps are converted to gray scale
        2.  Map applies to all surfaces of object, each object can have 1 displacement map. 
        3.  It is necessary for displacement maps to uniformly wrap around entire object.

Creating a Displacement Mapped Object

Choose Displacement Mapping option when creating an object, supported for Rectangle, Cylinder, Cone, Torus, Sphere shapes.

By default a procedural map is created for object.
 

Displacement Map Settings

With a displacement map object selected as Object A, open Object Effects dialog with Window: Object Effects menu option and choose "Disp. Map" tab.

Max Subdivisions: Controls maximum level of vertex granularity for each surface in object.  Higher values produce more vertices.
Regional Max Subdivisions: Allows level of vertex granularity to be set independently at Y poles for sphere shapes and Y
top/base surface for rectangle shapes.

Example sphere shown in Wireframe render mode with Max Subdivisions = 4 on left, 10 on right


User Defined Map Settings

Scale: Factor to apply to displacement map value.  Note displacement map value is in range 0 - 1, Scale value of 0 disables map
Inward Displacement: 'High' (white) areas of map produce inward negative displacement, by default displacement is outward.
Wrap S/T: Specifies how many times map texture coordinates repeat around object.  Note these are integer values
Map LOD: Specify mip level to use when sampling displacement map.  Higher values produce a smoother displacement result.
Scale Power: Applies power raise to displacement map value before multiplying by Scale setting, results in a smoothing or sharping of displaced effect.  


Note: These settings are available when a displacement map is set on object with Texture dialog.

User Defined Displacement Map Setup

Base map with corresponding displacement map

1.  Create a displacement mapped Sphere object
2.  Select a surface on Sphere object as Surface A
3.  Using Window: Textures dialog set base map to all surfaces of object
4.  Configure displacement map using Window: Object Effects and choose "Disp. Map" tab
5.  In example Max Subdivision is set to 20 and Variation map is disabled by setting it's Scale to 0

6.  In Textures dialog set displacement map to all surfaces on object, Wireframe and Solid Fill render modes shown



Variation Map Settings


Procedural Map Settings

From Disp. Map dialog tab usebutton to open Variation map dialog and choose "Procedural Map Layer" tab
Scale: Sets maximum vertex displacement range
Example showing procedural map result.  Settings are standard Perlin noise 

Interactive Map Settings

From Disp. Map dialog tab usebutton to open Variation map dialog and choose "Interactive Map Layer" tab

Scale: Sets maximum vertex displacement range

Brush Settings

X/Y: Sets brush shape and size
A: Rotates brush shape

Ellipse Specific Settings
    ES: "Ellipse Shape", varies shape of ellipse, shapes range from diamond/star to rounded corner rectangle
    Cut Out: Angular cut out section
    Cut Section: Angular position of cut out section

Cross Specific Settings
    Width 1/2: Adjust width of horizontal and vertical cross section

Gradient: Adjusts degree of edge fading for the brush shape
Center: Sets location of gradient, only available for sloped ellipse, rectangle brushes
Invert: Changes direction of brush gradient from outward to inward to inward to outward

Cyl Center Y Scale: Adjusts Y scale for brush shape when projected onto an object, *only for Cylindrical conformance

Match Object Scale: Brush counter scales with the object to maintain a conformal shape, otherwise brush will scale with the object, *only for Rectangular conformance

Brush Shapes
    Ellipse
    Rectangle
    Cross
    Sloped Ellipse
    Sloped Rectangle   
        Use sloped shapes for 'sloped' or gradient style displacements on objects

Brush Effect
    Effect applies to object vertices covered by the brush shape
 
    Additive: Displaces objects vertices outward or inward
    Flatten: Reduces displacement amount back to 0, no displacement, acts like a 'displacement eraser'   
    Average: Averages surrounding area vertex displacements, acts like a 'displacement smoothing brush'
    Procedural: Brush shape is blended with a procedural map as specified to create a non-uniform/random brush displacement inward or outward. 

    Note: Be aware that inward displacements can cause interleaved geometry and incorrect rendering, this can most likely occur at corner regions of an object, check wire frame view.  Brush effects only apply to interactive layer, total vertex displacement consists of user defined, procedural and interactive maps.

Applying Brush Effects

Create a displacement mapped object, move mouse pointer to a location within object in scene.  Click middle mouse button (as alternative use front side button,  middle button will be unreliable on mouse device without a center wheel ratchet).  Hold down button to drag brush location on object.



Circular shaped brush shown on rectangle object Mouse wheel, -/+ keys will apply displacement to object's vertices covered by brush
Brush color varies based on object's texture colors Outward displacement using additive brush effect

   

Inward displacement using additive brush effect

Brush Shape Conformance

Shape conformance effects how brush is projected onto objects. 

Spherical: Conforms to spherical objects
Cylindrical: Conforms to cylindrical objects
Rectangle: Conforms to rectangular objects (exclusively used for displacement mapped rectangle objects)


Rectangular brush shape on Spherical object


Where to use Cylindrical Conformance

Cylinder shaped areas conform best with cylindrical brush.  These include cylinder objects and elongated sphere center section which results in a cylindrical center region.  Spherical brush will not result in a conformal brush shape in cylindrical regions.

Spherical conformance in cylindrical region results in a distorted brush shape, example rectangle brush shown Changing to Cylindrical conformance results in expected rectangular brush shape Cylindrical conformance requires an independent calibration to counter object's elongating allowing brush to have same Y scale ratio in both cylindrical and spherical regions of the object.   
Use
Cyl Center Y Scale adjustment to calibrate in the Variation Map Dialog