learn. Jumpstart Vol.2 – Copy/Stamping from Adam Swaab

Picking up from where we left off in Vol. 1 - Procedural Modelling  explore the copy sop and ways to add variation to multiple objects in our scene.

The copy SOP is a vital part of Houdini and understanding this SOP, is critical to our learning trajectory with this software.  Adam  shows how to use template points as a basis for copying objects onto template points (similar to Cinema 4D’s mograph module), how to use attributes to control the scale, rotation and colour of those objects, and how to use stamp expressions to add variation to the objects.

In the final chapter, Adam shows how to take this knowledge to the next level, by creating a basic prototype of a forest of growing l-system trees, where each tree is a completely unique procedurally generated tree and the distribution is controlled by painting attributes onto a ground surface. (Note, the actual l-system functions are not explained in this tutorial).

This tutorial series is beginner level and assumes no prior knowledge of Houdini.

CHAPTER BREAKDOWN :

Chapter 1 : Intro

A quick overview of the lesson.

Chapter 2 : Introduction To Attributes

Starting with a basic line, we get our first introduction to attributes. We look at how point position, scale and colour are interpreted by the copy SOP.

Chapter 3 : Controlling Object Alignment

We now look at rotations, explaining how surface normals and up vectors control the alignment of objects copied onto our template points. We end the chapter by looking at a common mistake you can make by copying normals to your copied objects and the easy way to correct this.

Chapter 4 : Adding Variation With The Stamp function

We show two different ways of varying which objects are copied onto our points. In this chapter we get our first explanation of the group SOP. We look at the stamp function and how that can be used to add variation to our copied objects. Finally, we get our first look at the object merge SOP, showing how to bring objects from outside of our network into this one, so we can use them as copies.

Chapter 5 : Painting A Forest Of Animated Trees

We add one more layer to the system, by adding in an animated object, in this case a procedurally generated l-system tree (a simple tree prototype). We show how to use the paint SOP to paint where the trees will grow, show how to increase tree density, and then show how to procedurally randomise the timing of the growing trees.