Casting Shadows From Complex Shapes

Casting Shadows From Complex Shapes

Tutorial Goal

To learn a simple and versatile method of casting a shadow from any complex object in Adobe Photoshop. I find myself using this technique on a regular basis. Learn it once and reuse it the rest of your design career. It's a great way to quickly add a 3-Dimensional quality to a 2D design.

Resources Needed

A graphic to cast the shadow. You can choose anything you like or download the example Einstein Character provided below:
Einstein_example.jpg
Source: X-Power.com - An Algebra I Multi-Media Course.

Step 1 : Preparation & Document Setup

Open Adobe Photoshop and Create a new Image:
Size: 380 x 300px
(This is the size of the example background image)

Step 2 : Separate the Object from the Background

If your object is already on it's own layer skip this step. Otherwise separate the object from the rest of the background using the selection tools. For the example image provided the easiest way to separate the character from the white background is to use the Magic Wand Tool.

Select the Magic Wand Tool, , and using the properties below click anywhere in the white area.

Now with the white area selected, Inverse the selection to select Einstein.
Select > Inverse

Cut Einstein from the background and paste him into a new Layer.
Edit > Cut then Edit > Paste

You should now have a background layer and a layer with the object that will cast a shadow.

Step 3 : Create a Shadow Version of the Object

The entire object casts a shadow so we start with a 'perfect' shadow that matches the object's contours. Afterwards, we can distort, blur and fade the shadow into our desired effect.

Ctrl/Cmd Click the object's layer to select it's border.

Create a new layer, , above the object layer.
Layer > New > Layer...

Select the Paint Bucket Tool, , set the foreground color to Black and fill in the selection.

Before Einstein dishes out for his electric bill let's drag the shadow layer below Einstein and above the Background layers.

Now you have a shadow object that matches the contours of your complex object perfectly.

Step 4: Manipulating the Shadow

Time to take the perfect shadow shape and manipulate it into a more realistic shape.

First we'll distort the shadow to cast it across the ground. The final angle and length of distortion is completely up to you.
Edit > Transform... > Distort

Click and drag the handles to distort the shadow shape. A good place to start is the top, middle handle circled below.

I dragged it down and to the left. Drag individual corners to make minor adjustments to the shape.

Step 5: Blurring the Shadow's Edges

Unless your light source is a spot light the resulting shadow will blur at the edges. Don't believe me, take a look around your desk and observe the different shadows. So, let's blur the edges of our shadow.
Filters > Blur > Gaussian Blur

I choose a setting of 3.0 but tweak it to what looks good to you.

The shadow is still too defined. Let's reduce the shadow layer's opacity to 50%. This does two things, first it lightens up the shadow and secondly it will allow any texture beneath it to show through.

Step 6: Fading the Shadow

Looking good but it's too consistent don't you think? As a shadow gets further away from it's originating object it becomes less defined. Let's create that effect with another easy step.

With the shadow layer selected, click the 'Add A Layer Mask' button, , on the bottom of the Layers panel.

Now select the Gradient Tool, , and set it's properties to:

With the Mask Layer still selected, click and drag from the object across the shadow and release somewhere outside of it. The gradient fills white to black allowing 100% of the shadow layer to show through at point 1 and then fades to 0% of the shadow layer at point 2.

If you don't like the way the fade looks the first time, simply undo the gradient and reapply it until you are happy.

If Einstein is happy, I'm happy.

Casting Shadows From Complex Shapes:
Concluding Statements

Now you've learned a simple technique to create shadows from complex objects. Want to simulate two light sources? Simply repeat the steps for a second shadow casting in another direction. Hope you reuse this technique as much as I do. Until next time...