Inkscape Exercise: Draw Photorealistic Sphere
By Stephen Bucaro
Although Inkscape is a 2D drawing application, it is quite capable of drawing photorealistic
3D images. To demonstrate this capability, in this article I show you, step-by-step how to draw
a photorealistic sphere. Not only is it possible to draw photorealistic 3D with Inkscape, but
it's also very easy - which is really saying something when you're talking about a vector
graphics drawing application.
The reason Inkscape is so capable of drawing photorealistic 3D is because it's capable of
rendering millions of shades of colors, with varying degrees of transparency, and complex
linear and radial gradients. But to keep this example simple, we won't use any gradients.
That's right, the image above was drawn without using radial gradients. I did, however, use
blurs, which is very easy to do in Inkscape.
What makes a 2D drawing look 3D is the arrangement of light and shadow. Let's assume there
is a lamp to our left and slightly behind us which creates a bright spot on the sphere. This
is called specular light. The rest of the sphere is lighted by scattered and reflected light
from around the room. This is called ambient light.
The lamp creates a shadow on the opposite side of the sphere and also causes the sphere to
cast a shadow on the table top. Light reflected off the surface area of the table top
creates an area of reflected light within the sphere's shadow.<.p>
To create the sphere, draw 3 circles, all about the same size, as shown above. For the
first circle, set the Stroke style Width: to 0. Set the circle's Fill to the
ambient color of the sphere. Set the Fill blur to about 7 percent.
For the second circle, set the Stroke style Width: to 0. Set the second circle's
Fill to the color of the shadow side of the sphere. The Fill blur of the second circle
should be left at 0 percent.