This tutorial is a beginners guide to using splines with XGen and MtoA. It shows you how to create the hairs for a jumping spider model using a combination of XGen Splines and Maya's Paint Effects and deformation tools with Arnold's render curves. We will also cover ways to shape and deform the curves to create a more realistic result. Finally, we will shade and light the spider model itself to achieve a believable 'electron microscope' photographic look.

XGen Splines

We will create different descriptions for each body part. Let's start with the legs.





We can use XGen's brush-based grooming tools to style the hairs on the legs.


We will start by bending the curves downwards along the shape of the leg. 


Leg Shading



We can duplicate the leg description and use it for the body.


Noise modifier




We will use a Paint Effects brush for the head and then convert it to curves. This will give us more choice of tools once we have converted it to curves. This will then give us more control when it comes to 'shaping' the individual hair curves.

Paint Effects Brush

Select the 'furBunny' stroke in the Hair folder



Paint Effects Modifier

Currently, the stroke is intersecting the eye geometry. We want the stroke to appear to wrap around the eyeball. We can try to achieve this using a Paint Effects Modifier.


Sculpt Deformer

The 'Paint Effects Modifier' is not giving us quite the effect that we want and looks a little bit too random. We can instead use a sculpt deformer to deform the shape. However, we will have to convert the Paint Effects stroke to curves first and delete the Paint Effects Modifier.


Top of head

Paint Effects stroke - Global Scale 6


To pull the curves back so that they don't overlap the other side (we want to duplicate them across later), we can use a Lattice Deformer

Use a Lattice Deformer to shape the curves


Duplicate curves to the other side of the head (-Z direction).


Add Noise to Curves

At the moment the curves are looking very symmetrical because we have simply duplicated one group of curves to the other side. One way to reduce the symmetry is to add some noise variation to the curves. The sculpt deformer has an option to deform the curves using a texture map.



Override Set

  1. Ai Curve Shader
  2. Ai Curve Width
  3. Ai Mode
  4. Ai Render Curve


Add Override Attributes to Set




The body

The spider's body has a 'rim shader' assigned to it which gives the impression that the spider is photographed through an electron microscope. A sampler info node is connected to a ramp texture which is assigned to the Diffuse attribute of a Standard Surface shader.

Node editor showing body shader of Spider


The scene is lit simply with a large Ai Area light set to 'quad' that represents a large photographic soft box. Increase the samples to 3 for final rendering.





Thanks to Pedro Fernando Gómez for his assistance with XGen.