## Introduction

• This lesson will take you through setting up displacement with V-Ray
• This information centers around the basic displacement parameters
• The lesson topic is approximately 25 minutes in length
• Lesson covers all 3 Learning Cycles for the Lesson Topic – Lecture, Demonstration, and Activity

## Overview

 Goal - Use various displacement parameters to create different looksObjective – We will use several parameters to set up and alter displacement in a scene. Develop the look for a birdhouse model.       Outcome – You will understand how to work with the displacement parameters to  create a specific look

### Available materials

To set up the lesson follow the links below and download all available materials.

## Lecture

### 1. Terminology

Here are some terms to be aware of when thinking about displacement:

• Displacement
• The deforming of geometry based on maps
• Subdivision
• The dividing of geometry into smaller polygons

### 2. Displacement vs. Bump Mapping

• Displacement mapping alters the actual geometry
• Interactively subdivides geometry
• Suitable for large protrusion
• Alters the edges of objects
• Bump mapping does not alter the actual geometry

• Primarily a lighting effect

• Suitable for small bumps

• Does not affect edges of objects

### 3. V-Ray Displacement

a) Displacement Workflow Overview

• Add VRayDisplacement node to object via V-Ray Displacement button in V-Ray Shelf or by choosing Create > V-Ray > V-Ray Displacement in the Maya main menu
• Assign a map to the VRayDisplacement node
• Additional parameters available as Extra VRay Attributes (seen below)
• Once displacement is set up for one object, you can add more objects in Outliner to receive the same displacement

b) Parameters that affect displacement

• Displacement mat. (found in vrayDisplacement node) – this is the texture map
• Extra Attributes added through Attribute Editor to the object itself:
• Displacement Amount – adjusts how much the displacement affects the geometry as a factor multiplying the effect of the map
• Displacement Shift – adds or subtracts a constant value to the map
• Max subdivs – limits the amount of geometry subdividing to save memory and render time
• Edge length – the lower the value, the more accurate the displacement at the cost of render time
• Texture resolution – sets the resolution of the texture map being used
• Water level – clips the geometry away (creating a hole) when the displacement map values fall below the specified value

c) V-Ray Displacement shelf button

• Creates a VRayDisplacement node for selected object
• Parameters for displacement are set within the node

d) Displacement mat. slot

• Map that defines the displacement effect
• Only grayscale values used

e) Rendering of displacement

• Make sure that Displacement and Subdivision check boxes are enabled in Render Settings > Overrides > Geometry

f) Displacement Amount

• Sets degree of displacement

g) Displacement Shift

• Adds to the shift amount
• Amount = multiplication, Shift = addition

h) Edge Length

• Sets maximum edge length for subdivided surface
• Smaller values make finer mesh, at a cost of render time

i) Max subdivs

• Max number of subtriangles generated for each face during subdivision
• Expressed as square root: Value of 8 results in max 64 triangles
• Higher values = finer detail, lower values = faster rendering

j) Texture resolution

• Sets resolution of texture used by displacement effect

## Conclusion

a) Water level

• Visually clips the geometry below a specified planar level, as if the geometry were “under water”

b) Displacement mat

• Sets pattern for displacement as grayscale values

c) Amount and Shift

• Sets degree of displacement

d) Max subdivs

• Sets max number of face subdivisions

e) Water level

• Clips geometry

## Demonstration

Time to see it work!

Watch while I demonstrate how to set up displacement.

## Activity

Time to do it yourself!

Use the provided scene file to set up and adjust displacement.

We have also provided a final scene for your reference.

Dialing in the right values

• For planks:
• Displacement mat. – Planks_Noise
• Displacement Amount – 0.8
• Displacement Shift – -0.4