How to Create a Yellow Submarine Icon with Gradient Meshes
While spaceships, rockets and UFOs are all the rage in the icon world these days, submarines have been inexcusably neglected. Let's correct this situation immediately by drawing a fun submarine using gradient meshes, pattern brushes, opacity masks and blending modes.
You can find the source files in the directory labeled "source" that came in the files that you downloaded. You may wish to look through them briefly before we begin.
Step 1
Throughout this tutorial we will use gradient meshes to achieve beautiful color variations across the submarine's surfaces. Gradient meshes are extremely powerful but also one of Illustrator's most baffling tools. The most intuitive way to approach them is to create the final shape then convert it into a mesh.
Sadly, unless the shape is rather simple or symmetrical, Illustrator will convert it into a mostly unusable mesh, which leads to most people failing to get the hang of this tool. The correct way to work with meshes is the opposite: start with a simple shape, convert it into a mesh then manipulate its points to obtain the final shape.
Now to create the body of our submarine we start with a simple rectangle, turning it into a mesh with as little points as necessary to obtain the final shape.



Step 2
We have to turn this rectangle into an elongated ellipse, also applying perspective so the submarine will look like it's coming towards us. Grab the Direct Selection Tool (A) and manipulate the mesh points like you would in a normal path (2a).
The corners are rather tricky. You will find that you can't use the Convert Anchor Point Tool (Shift + C) to turn them into smooth Bezier points. Instead you have to manually align their two handles to eliminate any kinks and make the outline flow smoothly. With patience and practice create the final shape.
Note how the perspective emphasizes the front and top parts of the vessel. Make sure all the lines curve harmoniously together to define the round shape of the body (2b).



Step 3
Let's start shading the mesh. First select all points and give them a nice yellow color, then make the top and front points lighter and the bottom ones darker. Lighter means a less saturated yellow, darker means adding black to the base color but also a bit of magenta to introduce orange shades:



Step 4
Using the Mesh Tool (U) add two horizontal lines, halving the existing halves. Adjust the handles to make the lines flow smoothly, then, when you're satisfied with their shape, apply the correct shades to the new points. The goal here is to create a continuous, light-to-dark gradient that runs from top to bottom and from front to back. Again, this process will be time-consuming but it's important to get the shapes and the colors right before making the mesh more complex, as it will be harder to manipulate then.



Step 5
Add a vertical mesh line on the left. Expand the highlight to the front by selecting the second point from the top and sampling the light shade from one of the upper points. See how the bottom edge has a nice orange shade, the side is a full yellow and the front and top have bright highlights. Note also how the top highlight reaches the stern (the back) to simulate light coming from the water's surface.



Step 6
Add two vertical mesh lines, one to the bow (the front) and one to the stern (the back), adjusting their shape to match the submarine's round body (6a). To emphasize the light's direction (top and front) refine the shading, reducing the front highlight and expanding the orange shade to the back (6a).
Now we need to create a secondary longitudinal highlight along the topmost horizontal line. So create one line above it and one below (6b). Assign the new points the correct colors to keep the gradients smooth, then select the central points on the middle row and apply a light yellow sampled from the top. The new highlight will start from the front and will fade to the back (6c).
Our main body shape is now finished and looks really nice and complex with realistic, subtle color variations (6d).



Step 7
Let's add some detail to the body by creating rows of rivets across it. We will apply a simple pattern brush to paths that run across the body.
Create an ellipse (7a) then drag it into the Brush palette. A window will pop up (7b). Select New Pattern Brush and click OK. The Pattern Brush Options window will appear. Name the brush "rivets," set Scale to 4% and Spacing to 250% (7c).



Step 8
On a new layer create a new line to define the bow of the submarine (8a), snapping to the body's edges (activate Smart Guides with Command + U), and give it a yellow stroke. From the Effect menu choose Stylize > Drop Shadow and set the options as in 8b. Finally click on the "rivets" brush in the Brush palette and see the result (8c).



Step 9
Create three copies of this row of rivets, adjusting their shapes to match the submarine's body and positioning them progressively closer to each other as they reach the stern. This perspective hint is essential in letting us perceive the rows of rivets as placed regularly across the body (9a). Also create two horizontal rows using two additional copies of the first row, rotating them 90 degrees and adjusting their shape (9b).



Step 10
Let's give our submarine a few portholes.
On a new layer create a white ellipse (10a) then hit Command + C to make a copy and Command + F to paste it in front. Scale this ellipse down a bit (10b). With the smaller ellipse selected, Shift-select the bigger ellipse then in the Pathfinder click on Minus Front, the second icon from the "Shape Modes" row (10c). Name the resulting ring "outer rim."
Make a copy of it, name it "inner rim," send it to back (Command + Shift + Left Bracket key) and move it above and to the left to simulate thickness (10d). Give these rings smooth coppery gradients (10e, 10f).



Step 11
Now we'll add the glass window. Create an ellipse, send it to back (Command + Shift + Left Bracket key) and give it a smoky blue radial gradient (11a).
Let's add reflections to the porthole. Select the "outer rim" ring, copy it and paste it in front (Command + C, Command + F), then give it a black to white gradient (11b).
Next draw a curved shape (11c) and subtract it from the black to white ring using the Minus Front method explained before (11d). Adjust the gradient so there's less black (11e), then from the Transparency palette change the Blending Mode to Soft Light (11f).



Step 12
Now Let's add depth and reflections to the glass window. Hide everything except the glass. Duplicate this ellipse, scale it down and move it a bit to the left so there's a thin blade of the bottom ellipse showing. Give it a black to white radial gradient, change the blending mode to Darken and lower the Opacity to 50% (12a). This will give the window some thickness.
With this last ellipse still selected, copy it and paste it in front. Change its gradient from Radial to Linear with the black on top and lower the Opacity to 35% (12b). This will add a shadow to the top of the window.
Again, copy and paste in front the last ellipse. Using the Minus Front method, subtract from it a curved shape (12c). Adjust the gradient of the resulting shape so the white is on top. Change the blending mode to Screen and set the Opacity to 50% (12d). Now the window has a reflection.



Step 13
Unhide both outer and inner rims, select all objects (Command + A) and group them (Command + G). From the effect menu select Stylize > Drop Shadow. The shadow should be darker than the submarine's body but not black.
The Multiply mode should be selected by default. Adjust the other parameters to obtain a fairly soft shadow (13a). The porthole is finished! Just make two copies and position them along the body, using the rows of rivets as guides. Progressively reduce their mutual distance and their width to account for the perspective (13b).



Step 14
To create the sail follow the instructions in the next image. Make sure to work a new layer to keep things tidy.
- Draw the base of the sail then duplicate it. Scale down the copy and position it above to make the top (14a).
- Switch to Outline View (Command +Y) and draw straight connecting lines, snapping to the curved shapes. Lock the straight lines (14b).
- With the Scissors Tool (C), cut the base of the sail where it intersects the straight lines. Erase the resulting upper half (14c).
- Copy and paste in front the sail's top, hide the original. Repeat the previous step, cutting the shape in two and erasing the upper half (14d).
- Unlock the connecting lines. Use the Direct Selection Tool (A) to select each corner of the new shape then hit Command + J to join the two points, choosing the Corner option (14e).



Step 15
Let's shade the sail. Select it then choose Object > Create Gradient Mesh, then set 2 Rows and 4 columns (15a). Refer to the next images for the steps necessary to create the final mesh. Our goal is to create a frontal highlight and have the sail go darker towards the back and bottom.



Step 16
Now let's add a reflection at the base of the sail. Make a copy of the sail's mesh. We want to turn it back into a path. Select Object > Path > Offset Path and use 0 as offset (16a). Erase all the upper points, leaving a single path (16b). Give it a 1px light yellow stroke and a 2px Gaussian Blur by going to Effect > Blur > Gaussian Blur (16c).



Step 17
The sail projects a shadow onto the main body. Draw a shape that conforms to the submarine's curvature (17a) and give it a flat, dark orange fill. In the Transparency palette, set the blending mode to Multiply and Opacity to 65% (17b). We now have a solid, hard-edged shadow but in reality shadows fade and blur as they recede from their base. So let's add an opacity mask. Copy and paste in front the shadow and apply a white-to-black linear gradient (17c).
Now select both objects, click on the arrow icon in the upper-right corner of the Transparency palette and, from the drop-down menu, choose Make Opacity Mask - the shadow now fades away from the sail. Whenever you create opacity masks remember that white lets objects through and black hides them, just like in Photoshop. Apply a 5px Gaussian Blur to the shadow (17c).



Step 18
We have a problem now: even though most of the sail is in shadow, the highlight at its base is fully bright throughout its length. That's wrong. Let's correct this.
Copy and paste in front the highlight (you are now experts in hitting Command + C and Command + F), remove the Gaussian Blur from the Appearance palette, adjust the Stroke to 2px then choose Object > Path > Outline Path (18a).
Fill this shape with a white to black linear gradient, making sure the white fades into black from left to right (18b). As we did before, select this shape and the highlight then make an opacity mask. Now the highlight is more consistent with the lighting (18c).



Step 19
On to the foreplanes, draw a lengthened teardrop shape with a pointed end (19a), it will be the foreplane's side. Draw the length of the foreplane (19b) and fill it with a vertical gradient to brighten the top, darken the bottom and highlight the front (19c). The side needs to have a gradient too. Now it looks good (19d).



Step 20
To add a highlight to the foreplane's edge, duplicate the side and remove the bottom points (20a). Give this path a 0,5px pale yellow stroke (20b). Same as before, duplicate the path, outline it, add a black to white gradient (20c). Make the opacity mask then apply a Gaussian Blur (20d). The foreplane is finished.
Make a copy, move it behind the sail then adjust its size and position to match the perspective. Modify the gradient to make it brighter as the second foreplane is in direct light (20e).



Step 21
Of course the right foreplane casts a shadow onto the sail. Draw the shadow and fill it with the same dark orange as the sail's main shadow. Just like we did before duplicate the shape, add a black to white gradient, make an opacity mask then blur the resulting shadow (21a, 21b).



Step 22
Let's create the periscope. Make a copy of one of the portholes, flip it horizontally, scale it down and modify the color of the rims to gray (22a). Using guides (22b), draw the periscope's pipe and fill it with a medium gray (22c).
Next draw two lines along the pipe (22d). Apply a light stroke to the inner line and Blur it (22e). Apply a dark stroke to the outer line and Blur it too (22f). Group the two lines. Make a copy of the pipe, bring it to front (Shift + Command + Right Bracket key). Shift-select the blurred lines then hit Command + 7 to make a clipping mask so the blurs will be constrained to the pipe (22f).



Step 23
The periscope needs a reflective highlight also. Create a white ellipse (23a), convert its top and bottom anchor points to corners by clicking on them once with the Convert Anchor Point Tool (Shift+ C) (23b). Scale, position and align the shape on the periscope's pipe (23c) then reduce its opacity and blur it (23d).



Step 24
Let's draw the tailplanes now. Make a copy of the foreplane's side, scale it down, position it near the stern of the submarine and make it darker (24a). Next draw the rest of the plane, filling it with a multi-color gradient similar to the foreplane's but darker (24b). Finally copy the foreplane's shadow, place it beneath the tailplane and adapt its shape to match the new location (24c).



Step 25
The final step is to draw the propeller. Draw a blade with a single path (25a) then convert it to a Gradient Mesh. Refer to the picture for the shading (25b). Make three copies and arrange them at 90° angles. Draw a circle for the hub. Fill it with a soft radial gradient and give it an Outer Glow (Effect > Stylize > Outer Glow) (25c).
Select and group the hub and the four blades. Move the propeller behind the submarine's main body and squash it horizontally. You might need to shear it vertically a bit to match the perspective. Do that by right-clicking on the propeller and choosing Transform > Shear (25d).
Only three blades remain visible. Their shading needs to be adjusted to account for the submarine casting shadows on it. Also the bottom blades are almost completely in shadow. Just sample colors from the submarine's main body and you'll be alright (25e). We're finished!



Conclusion
Let me tell you, this was a lot of fun to make. We've covered many techniques: gradient meshes, pattern brushes, opacity masks and blending modes. They are all very simple when taken individually but when combined they become extremely powerful. The most important aspect when creating realistic illustrations is to pay extreme attention to perspective and shading. Picking a consistent point of view and a clear direction for the light makes this job much simpler.
I hope you enjoyed this little tour-de-force as much as me and I hope you learned a lot. Now go start a new trend in icon design - submarines!



