Carey House Tutorial 05 - Pool

Water is always a tricky thing to get right but also enjoyable to develop as it can really bring a scene to life.  In the Carey House there is only one small area of water, visible in only one or two views but I think it's worth dedicating a tutorial to as it may provide useful tips for many situations.

There are three basic steps to create this shallow reflecting pond.  
1. The water texture
2. The wet edge
3. The pebbles

There are many way to produce water in 3d.  And different techniques suite different environments.  We have used bump, displacement, 3d vector based displacement (Chaosgroup's Phoenix and similar), simulation, particles etc...for different applications.  In this instance however we have simply used bump to reduce render times and simplify geometry.  It also means that when we make this scene available for purchase, no additional plugins will be required for the water. 

The basic material is similar to glass but with a reflection glossiness of 0.8 and a Fresnel IOR of 1.6 rather than 1.8. The refractive IOR is 1.33 for water generally giving the impression of the pool becoming shallower as the angle of incidence of the camera increases.  Two noise maps of differing sizes are comped together with a large noise map masking between them.  Note that in this case we wanted the ripples to look like they were slightly running across the pool as if a gentle breeze may be blowing from one end. This is achieved by adjusting the x and y tiling coordinates in the noise map parameters effectively stretching map. 'y' is approximately five times 'x' in this example.

The wet edge of the concrete pool was made with a blend material to give the impression of water having splashed up out of the pool. The basic dry concrete material was copied and made almost entirely reflective by deleting the reflection and reflection glossiness maps and simply applying a light colour to the reflection channel (approx 210). A painted black and white bitmap is used to blend the two materials.  The stepping stones along side the pool are textured in the same way but with a noise map used to blend the two materials. 

To add another level of detail the bottom of the pool is filled with pebbles.  Firstly a gravel base was created with a VrayDisplacementMod as in the driveway tutorial.  The large pebbles which were scattered with Forest Pack Pro amongst the grass in the first Carey House tutorial are used to full the pool.

The Forest Pack settings are similar to those previously described for the gravel drive.  Two points to mention are boundary checking which is set to size to prevent scattered objects from extending past the surface upon which they are scattered and collisions.  In this case collisions are not enabled as it was not necessary due to the fact that the pebbles are obscured by reflection and refraction beneath the water and it was easier to achieve the desired density without enabling collisions.

Forest Pack Pro dialogue

The final scene was a dusk shot with a strip light illuminating the pebbles which is why we went for scattered geometry rather than displaced.  Quite a nice but relatively simple effect.

In the next tutorial we will have a closer look at HDRI lighting of the scene and see what can be achieved with the peerless PG Skies.