Introduction

This tutorial will show you how to assign colour to a model based on altitude.

Setup Blender for Procedural Colouring of Terrain

We'll be creating nodes to find the altitude and then assign colour. Download 01 Start - Stewart Island.blend which contains an island to colourize. The UI has been changed a little to show the Node Editor. Increase the quality of the model if you wish by increasing the level of Subdivisions:-

01 Change render engine from Blender to Cycles:-

Add new nodes

03 We need to ask Blender for the position of the model, extract the Z height range, and assign a colour gradient over that range. We will create three nodes and link them to the Diffuse BSDF node:-

Geometry - Separate XYZ - ColorRamp - Diffuse BSDF - Material Output

1. Add >> Input >> Geometry
   SHIFT A ... I ... G
   LMB on the left of the screen to place node.
    
2. Add >> Convertor >> Separate XYZ
   SHIFT A ... N ... P
   Place this node to next to the first.
    
3. LMB DRAG a connector from Position to Vector.
   


4. Add >> Convertor >> ColorRamp
   SHIFT A ... N ... C
   Place this node next to the second.
    
5. LMB DRAG a connector from the Z to the Fac.
   
    
6. LMB DRAG a connector from Color to Color.
   

Add Colours to the Colour Ramp

Click the button to add in as many colour stops as you desire. Select a colour by clicking on the  button and adjust by clicking on the colour box:-


You can copy colours by moving the mouse pointer over the colour box and pressing CTRL C and then change to the next stop and paste the colour with CTRL V.

Do this for each colour. You can adjust the stops by LMB dragging the . For greater precision use the position field:-
and cycle through the stops using

In this model the sea and beach may look nice if they're quite close together. E.g.:-

Files

• 01 Start - Stewart Island.blend
  This is the file to start this tutorial with.
• 04 Colour Ramp.blend
  This file is the end result of following this tutorial
• NZDEM_SoS_v1-0_29_Invercargill_gf.png
  Sourced from University of Otago who have released it under Creative Commons Attribution-Share Alike 3.0