Moonlight is not all that difficult
to create, but can vary in intensity as the month progresses. The
weather can also effect it’s intensity on an hourly basis,
so if you want the full effect, you may have to take in these considerations.
We’ll concentrate, for the best part, on a full moon on a
slightly cloudy night. These can create interesting effects in the
clouds as the moon shines through which are nice to recreate in
On a full moon, yet ever so slightly
overcast, you will notice that the sky is lit up and that the illuminated
subjects on the ground are lit using a diffusion method from the
ambient light emitted from the refracted light from the clouds.
These refractions can also create a unique “Halo” effect
that almost looks like a lensflare ring in the clouds themselves.
Observe the real thing, if possible
and start by breaking the scene down into it’s individual
layers. Firstly we have the starfield background; this can be generated
either by using a procedural or bitmap background. For this example,
we will use the latter due to the inclusion of the Milky Way as
a background image, which would be slightly difficult to reproduce
as a procedural!
Next comes the Moon itself; this can
either be integrated either as a decal onto the starfield map or
as a standalone object. Again, we will use the latter for this example
should we wish to easily perform any additional glows or other post
effects on the Moon. Instead of using a wrap-around cylindrical
map for this object, as we are only viewing the moon from the front
and not the “dark” side, then we shall use a single
planar mapped image of a photograph of the moon itself as this is
what you would see if you looked up into the night sky.
Finally, we come to the cloud layer.
This normally consists of a cylindrical map wrapped around a hemisphere
as a skydome. Actually creating the night sky cloud layer can be
slightly taxing as it is difficult to photograph clouds to create
this texture at night. Therefore a daytime panorama is taken and
the blue removed and replaced with black to generate transparency
in the skydome so we can see the moon and stars in the background.
As the moon is positioned behind the cloud layer, some backlighting
of clouds will be present which causes the clouds to glow the “closer”
to the moon they are. This effect is generated using a Gradient
Ramp map in the self-illumination slot of the Cloud’s material,
assigned to an additional map id on the skydome, with the UVW map’s
gizmo positioned in front of the moon relative to the active camera.
To create the diffused lighting effect,
position several lights around the moon so that the intensity of
the specific light fades the further it is positioned away from
the moon; more intense around the moon and gradually fading off
into background light. A relatively small array of lights should
be created to simulate this effect ranging from intense with harder
shadows to background light with soft diffused shadows. Creating
this array will also generate an Area light effect with the shadow
more intense at the base of the illuminated subject which then fades
off and disperses.
You will notice that in any moonlit
situation that the rear of illuminated subject is not entirely black;
some light is reflected back of additional surfaces and even rear
clouds that are lit by the moon, so you will have to place lights
accordingly. These lights should be more “cool”; colder
colours such as a slight tint of blue or purple to bring out the
contrast. Slight uplighting should also be used, especially if working
with reflective surfaces.
create a Skydome hemisphere to completely encompass your scene
and scale it vertically as necessary. This should be a simple
Geosphere primitive set to hemisphere. Add a Normal modifier
to it’s stack and check on Flip Normals. Add a UVW map
to the skydome’s stack and set it to cylindrical mapping.
You may wish to delete the base faces of the skydome or position
them slightly below your ground as they may intersect with the
rest of your scene. Create another UVW map and set it’s
ID to 2. Position it as illustrated.
another Geosphere primitive so it is several times larger than
the skydome as illustrated in the screenshot. Add a Normal modifier
to it’s stack and check on Flip Normals. Add a UVW map
to the Galaxy Geosphere’s stack and set it to spherical
another Geosphere primitive and position it against the backdrop
of the Galaxy Geosphere and behind the Skydome. Reposition,
Scale or resize it so it is prominent in the scene’s camera.
Add a UVW map to the stack and ensure that the planar map’s
Gizmo is facing the camera. Reposition the second UVW Map’s
Gizmo of the skydome so the center of the gizmo is over the
center of the moon as viewed from the camera.
a new material and label it Galaxy. Assign it to the Galaxy
geosphere. Create a new Mask map in the diffuse slot. In the
Mask map, create a new bitmap map in the Map slot and load in
a starfield background image. Clone the bitmap into the Mask
slot. Crank the material’s self-illumination spinner up
to 100. Create a new material for the moon and load the “moon.jpg”
bitmap into the Diffuse slot. Instance copy this into the Self-Illumination
slot and check on Self-Illumination.
a new material for the skydome and load in the “sky night.bmp”
bitmap into the diffuse slot. Instance copy this into the Opacity
and Bump Slots. Check on Self-Illumination and create a Mask
map in the Self Illumination slot. In the Mask map’s Map
slot, create a Gradient Ramp map, design the gradient as illustrated
and ensure that the Gradient type is set to radial and the Map
Channel set to 2. Copy this Gradient into the Mask slot and
amend the gradient so it runs white to black.
lights as illustrated around the moon Geosphere, with varying
intensities from 0.75 over the moon to a grey 0.1 intensity
light overhead. Also, create fill lights around the illuminated
subject(s) with diffused shadows. Create additional post effects
such as blur if required to generate a little specular bloom
to the image and to intensify the glow around the moon.
before render – here we can see the layers used to complete
the scene. Each layer is quite low polygon and is positioned
relative, so the stars will pass behind the Moon which passes
behind the clouds.
final render. Additional post effects have been used to blur
the clouds and moon slightly. Note the use of self-illumination
in the clouds and the introduction of the coloured ring effect
caused by light refraction.
to accompany - On loading the max file, you may need to reload
the maps included in this zip file or include the relevant folder
on your local drive that contains the extracted files as a path
within max. Ensure that the Moon's material points to the moon.jpg
file on the cover cd and NOT the one included with max as these
files are different.
skydome’s clouds, although just a cylindrical mapped bitmap,
can be easily animated (as shown in the sample max file and resulting
render included on the cover cd). Use either a Volume Select modifier
or Mesh Select and select the top vertex of the skydome. Check on
SoftSelect and increase the amount until the base of the hemisphere
is slightly affected. Add an Xform modifier and animate the Xform
gizmo rotating to 60 degrees, so it twists the mesh. Looking directly
forward it will appear as the clouds are moving, but do not move
or pivot the camera too far else the illusion will be lost.
a little more intensity to the brightness of the moon and the reflections
off the surface(s) by adding a Blur effect to the scene to add a
little specular bloom. Don’t go overboard though as this can
dramatically blur the image. Also try using material changes to
the clouds (to a raytrace material) and glow effects on the moon’s
material id to create this effect.
elements could be included in the night sky to add extra realism
and ambience. The occasional shooting star, flock of birds or aeroplane
(white dot!) flying overhead hilited by the intensity of the light
eminating from the moon can add emphasis on it’s brightness.
of simply using a cloud bitmap on a skydome for the clouds, try
using a particle system or plugin to generate these cloud effects.
Volumetric cloud plugins such as Afterburn or Pyrocluster will be
ideal in these circumstances and the lights positioned behind the
clouds should produce a backlit effect on the volumetrics, therefore
creating the glow we had to produce with the additional UVW map.
World magazine, Issue 28, August 2002.
Draper, August 2002. Reproduction without permission