How to Place Water-Drop Highlights and Shadows from a Consistent Light Source

Before shading, draw an arrow outside the picture pointing from your imagined light toward the drop. For this exercise, use light arriving diagonally from the upper left. Keep the supporting surface approximately parallel to the picture plane and view the drop from slightly above.

Also decide whether the source is small or broad. This affects more than brightness: Blender’s official lighting documentation explains that increasing a light’s size softens shadows and specular highlights. A broad source therefore calls for a different treatment from a tiny, concentrated source. Blender Manual: Light Objects

For the first study, choose a plain surface with a middle value and one dominant light. That is a practical drawing choice: it leaves room to show both lighter and darker marks without introducing a complicated reflected environment. Keep your viewpoint fixed while comparing the drop with a reference.

Water can reflect light at its surface while transmitting light through it. UCLA’s ray-path demonstration shows these as separate paths: some incoming light reflects immediately, while some enters the drop and emerges again. Those paths explain why a drop can contain more than one bright feature under one light source. UCLA ePhysics: Physics of rainbows

The specular highlight is the visible reflection of the source. Its location depends on the light, your viewing direction, and the local tilt of the curved surface. The law of reflection requires equal incoming and outgoing angles relative to the surface normal—the imaginary line perpendicular to that surface. Physically Based Rendering: Specular Reflection and Transmission

For our chosen view, place a small highlight inside the upper-left portion of the drop. Leave space between it and the outline. Think of it as a reflection sitting on a curved surface, rather than a white mark attached automatically to the edge.

A second bright area can come from light traveling through the drop. Refraction bends that light; the resulting brightness is a different feature from the surface reflection. Dietrich Zawischa’s photographed spherical-water demonstration likewise distinguishes the front-surface image of a lamp from light following paths through the water. Refraction and dispersion of light

Peter Weatherill’s coloured-pencil demonstration uses a useful arrangement: a highlight toward the light, a cast shadow opposite it, a darker upper interior, and a lighter lower rim. It also lets the underlying surface colour show through. These are helpful drawing cues for the demonstrated setup, rather than compulsory marks for every drop. How to Draw a Water Drop in Coloured Pencil

Use the following map as an illustrative plan for the upper-left lighting exercise. The locations describe the picture, not universal optical coordinates.

Feature	Starting placement	Drawing decision
Source reflection	Inside the upper-left portion	Reserve a small, clean light shape
Dark interior tone	Near the upper or source-side interior	Blend inward rather than drawing a solid stripe
Transmitted bright area	Toward the lower-right interior or rim	Keep it broader and distinct from the source reflection
Cast shadow	On the surface, extending lower right	Connect it visibly to the drop’s footprint
Boundary accents	Selected sections of the perimeter	Vary their strength instead of outlining everything

The distinction between inside and outside is essential. A dark patch seen through the water belongs inside the silhouette. The cast shadow belongs on the receiving surface. Label them lightly on your practice sketch if you keep confusing the two.

Use this sequence to turn the placement map into a finished study. It is an editorial working method derived from the reflection and refraction principles above; it does not predict an exact optical pattern.

1. Establish the background value. Make a small, even patch of middle tone. If working digitally, use a background layer beneath the drop.
2. Sketch the footprint lightly. Choose a rounded, slightly irregular oval. Keep the construction line faint enough to revise.
3. Reserve the source reflection. Mark a small shape in the upper-left interior. In pencil or transparent paint, preserve the paper there; digitally, keep it on an editable layer.
4. Locate the cast shadow. Add a restrained shape immediately outside the lower-right boundary. Establish its direction before deepening it.
5. Build the interior values. Introduce a darker upper-side area and blend toward a lighter lower-right area. Preserve some of the background’s colour or texture.
6. Refine the boundary. Strengthen only the segments needed to describe the footprint and separate adjacent values.
7. Finish the reflection. Clean its shape and adjust its brightness after the surrounding tones are established.

Pause after step five and view the study at its intended display size. If the drop is unclear, identify which relationship is missing: the reflection, the interior value change, or the connection to the surface. Adjust that relationship before adding more detail.

For coloured work, begin with the supporting surface’s colour family. Weatherill’s demonstration uses the leaf’s greens and browns within the drop and shifts the underlying detail to suggest optical distortion. Avoid assigning blue simply because the subject is water. How to Draw a Water Drop in Coloured Pencil

Do not treat the cast shadow as a uniformly filled silhouette. A transparent drop redirects light as well as reflecting it, so examine the reference for light interruptions or concentrated brightness around its shadow. The underlying mechanism is refraction: transmitted rays change direction at the boundary between media. Physically Based Rendering: Specular Reflection and Transmission

In the practice drawing, begin with a modest lower-right shadow and leave yourself room to modify it. If the reference shows a bright patch within or beside that region, preserve it. Do not add a bright crescent merely to complete the placement map.

Match edge treatment to your selected source. A relatively small source supports crisper shadow boundaries; a broad source supports softer ones. Blender’s manual explicitly describes area lights as producing soft shadow borders and contrasts them with point-like sources. For drawing, this gives you a useful consistency check between the source you imagine and the shadow you paint. Blender Manual: Light Objects

Keep the reflected highlight and the transmitted bright area visually separate. For this exercise, try a compact, clearly shaped reflection and a broader, gently graded interior light. These are deliberate artistic choices that make the two roles easier to read; adjust them when your reference shows otherwise.

Once the first drop works, add two nearby drops of different sizes. Keep the same surface, viewing direction, and dominant source. Use the original arrow to check the general direction of their cast shadows.

For a distant source, approximately parallel lighting is a useful assumption. A nearby point source produces directions determined by the line from the source to each surface point, so shadows may fan outward across a wider composition. Blender’s manual documents both the single-direction sun-light model and the position-dependent direction of point lighting. Blender Manual: Light Objects

Use three separate checks rather than copying the finished first drop:

• Direction: Does each cast shadow agree with the source position?
• Reflection: Could each main highlight plausibly reflect that same source toward the viewer?
• Shape: Have you allowed the interior pattern to change where the drop’s curvature changes?

The last check matters because refraction depends on the surface orientation encountered by each ray. An irregular drop therefore needs interpretation, not a rotated copy of a circular-drop diagram. Use the map to organize observation, then follow the actual shape. Physically Based Rendering: Specular Reflection and Transmission

Use this table when the drop looks unconvincing. Each correction is a drawing experiment: make one change, compare the result, and keep it only if it improves the intended lighting.

What you see	What to inspect	First adjustment to try
A solid bead	Interior values are shaded like an opaque object	Restore some background colour and a transmitted light area
A flat circle	The perimeter carries all the contrast	Reduce the outline and develop the interior value change
A floating drop	The external shadow is detached	Bring the shadow back to the footprint
Conflicting lighting	Shadow directions disagree across drops	Recheck every drop against the light arrow
Several unexplained white dots	Every bright feature has been treated as a reflection	Identify the main source reflection and simplify secondary marks
A mechanical repeated pattern	Every drop has identical marks	Reassess the marks against each drop’s individual shape

Finish by tracing three imagined paths: from the source to the surface reflection and your eye; through the water toward a transmitted bright area; and past the drop onto the receiving surface. Keep those roles clear, and your highlights, interior tones, and cast shadows will have a coherent structure you can refine through observation.

• Specular Reflection and Transmission — Physically Based Rendering, Fourth Edition
• Light Objects — Blender 4.5 LTS Manual
• Physics of rainbows — UCLA ePhysics
• Refraction and dispersion of light — Dietrich Zawischa
• How to Draw a Water Drop in Coloured Pencil — Pencil Topics