Let’s take the gradient fill to the next level and work with colour and alpha to create a simple underwater background. Colours in Inkscape are defined in various formats. The most common are RGB for digital display and CMYK for traditional printing. RGB mixes the values of 3 colours red, green and blue to mix all others. In addition, there is RGBA with an added alpha channel. This defines the transparency of the object. The value 255 is fully visible. Going down to 0 for totally transparent.
In this tutorial, we will make use of this feature in our gradients.
Start with a rectangle.
Use the gradient tool to create a linear fill. The light intensity drops as you go deeper underwater.
Add a duplicate below and edit the gradient fill to more brownish colours for the sea floor. Use the gradient tool to create a linear fill. The light intensity drops as you go deeper underwater.
Change the rectangle to a path and modify the nodes.
Add two more copies and make them lighter.
Create another rectangle for a ray of light using a linear gradient with the alpha set to 0.
Change the setting to 50% alpha at the top and 0% at the bottom. Use the node tool to widen the base.
Use the skew modifier (double click) to angle the ray of light.
Add duplicates and modify their skew and nodes. A few semi-transparent circles add to the underwater feel.
This is the ‘bare bones’ setup of an underwater scene. There is a lot to add, from rocks, to reefs, corals to fish… If you are unsure what to add, I advise a good look at “my friend google”… Do an image search whenever you need inspiration or are not sure how things look. It usually gives you a good idea where to start.
Let’s add some decoration – first up: some bubble. Start with a semi-transparent white circle…
…with two copies [one slightly smaller] combined to a ring (Path/Difference)…
… and another three for some highlights.
Next up: a sea anemone. Starting with a rounded rectangle…
… converted to a path and modified at the nodes forms the base.
Some deformed circles turn into the tentacles.
Copied, placed and rotated they start looking right.
By applying a linear gradient to the front and base…
…and highlights to the top we adjust the light to match the top down light our underwater scene.
Hint: Use the ‘Page Up’ and ‘Page Down’ key to adjust the order of objects [e.g. place the sea anemones in the mid-ground behind the light rays.]
Adding Visually Interesting elements
I would like to add more life to the underwater scene and create some fish. The basic principle when adding ‘real’ elements to a vector scene is to look at the shapes and ‘deconstruct’ them into basic elements like the circle, square, rectangle or ellipse.
I usually do a quick google image search for a reference image to get a better idea of what I am going to create. In this case, the ‘yellow reef fish’ search came up with a nice yellow longnose butterflyfish.
It works great as the main body is kind of squarish and the front has a triangular shape.
Get to it
A ‘longnose butterflyfish’ would make a nice and colourful fish for our scene…
…and pose a more complex combination of shapes. Let’s start with a rectangle.
Convert it to a path and modifying the nodes creates the basic body shape.
Two more rectangles will form the head…
… by simply moving the two corner nodes inside.
Time to add some circles…
and modify their nodes to create the desired shapes.
Duplicate those and put them in place…
…with some colour variations, the same shapes function as shading and add detail to our fish.
The same approach works the same with far more complex elements. It’s a matter of seeing the ‘building blocks’. Break it down to simple shapes and combine it to something more complex.
Get the source art (svg file) of this tutorial for free!