Adidas X18+ Soccer Boot Surfacing

We are going to learn to model the Adidas X18+ soccer boot using surfacing techniques.
These are the cleats worn in 2018 by Luis Suarez and Mohamed Salah, among others.

The preferred software for this tutorial is Solidworks but any program with comparable surfacing techniques such as CATIA, Rhinoceros and Alias will work. It is an intermediate course because we are touching on advanced surfacing techniques but only develop a basic model of the shoe that can be developed much further.

  1. Step 1: Projections

    First, make sure to at least have a blueprint for the top, bottom and side views to model from. Often you can obtain these simply from the manufacturer's website.

    The preferred way is to set these at a 50% transparency and mute them to a low contrast black and white image. Sometimes it is better to put these sketch images on planes that are offset from the base XYZ planes so you do not have to put the 3D model to transparent in order to see the blueprints.

    Now, the entire shoe upper is basically lofted from the back to the front, with separate surfaces for the inside and outside section. The origin of the world XYZ is in the center of the foot insertion hole to greatly aid the modeling process.

    At the bottom, this loft will be limited by the sole outline and at the top by the insertion hole, so we model these first.

    Note that we draw the insertion hole on a plane offset from the Top Plane called P1 Top Pro, from which we will also project all curves to cut and add details to the upper. The insertion hole curve is drawn in four quadrant sections, all connected to and perpendicular to the Front and Right Plane.

    The sole surface is a loft from one horizontal line on the Front Plane to one on an offset plane called P2 Front Sec, which defines the shape of the shoe through the ball of the foot. At the sole, the profile line here is at an angle compared to the one on the heel and about 6mm higher at the outside of the foot. The simply loft with a profile curve as a Guide curve.

  2. Step 2: Bezier Curves

    In this step we draw all defining curves for the inside of the shoe. First we trim the shoe loft surface with an outline. Then we draw profile curves at the heel, the ankle and the heart line cutting through the center of the upper. The shoe's main loft for the upper is divided into three sections: one for the heel, one for the mid section from the ankle towards the ball of the foot, and the toe box section at the front. The heel section is defined as a loft between the two lines in blue in above image, with part of the foot insertion hole and sole as guide curves. The toe box is a loft between the orange and black curves. The section in-between, let's call it the Instep, is a fill surface with tangency controls.

    Draw the heart line as a complete Bezier curve first in a single sketch, then in two new sketches replicate the two parts of this curve for respectively the middle and front toe box section using the 'Convert Entities' command.

    When drawing Bezier curves always limit your anchor points to three, four at most. For added continuity, define the curvature controls at the end anchors and equalize them for continuous curves.

  3. Step 3: Surfacing the Upper

    Do the same as done in Step 2, now for the outer side of the shoe. Note that the profile through the outer instep section on P2 Front Sec has a flatter section to the Bezier, this is for defining the area that regularly hits the ball for power kicks.

    When all your surfaces have been completed, evaluate them with Zebra Stripes and Curvature display under the Evaluate tab. In the image above, the curvature across the outer ankle section can be smoother, otherwise it looks fine.

  4. Step 4: Sole Transition

    When all surfaces are there, knit them together including the sole. A variable radius will provide almost the entire organic transition that we are looking for, especially if we can employ curvature tangencies. It is also possible to utilize asymmetric fillets with a hold line further from the meeting point of the surfaces at one side than the other, as we will show.

    Because the sole is very narrow under the arc of the foot, the fillet is much larger at these areas. At the inside, also called the cookie part because one could neatly fit a cookie underneath the shape of the foot here, we delete the single face defining the 35mm fillet after it has been completed. Then we create a loft there instead so we can control the exact curvature, and as a result, the narrow shape of the sole.

  5. Step 5: Sole Trims

    Because our shoe is tangent across the center both at the front and heel section, we can define two curves at the Right Plane to split the sole section in different ways. On the outside of the shoe, there is a small wave section which we first draw as a simple step in a curve (see above). Then in a second step we copy this curve using 'Convert Entities' and round the curve before trimming.

    We have cut out the foot insertion hole shape too at this point, using a simple projection from the Right Plane. Add another trim sketch at the Front Plane for adding definition to the heel collar.

    Also before trimming, we copy the base lofted surface to make for the other elements of the shoe:

    1. The original surface for the sole
    2. The first copy for the upper
    3. The second copy for the tongue and details on the vamp
    4. The third copy for the inside including the insole

  6. Step 6: Detailing the Upper

    Always define a shape as much as possible perpendicular to the surface that shape is on. For the tongue shape, we define the lower tip of the tongue on the midsection from the top projection plane above the shoe. To not intersect with the sides, we first split the shoe in one area that we will use for the tongue shape projected from above, and the other two remaining areas for the shapes projected from the side. Note in above image the projected shape in orange positioned in between the angled lines defining the split section.

    Now similar to splitting the sole in two sections, we split the upper in two sections with projected Split Lines from the Right Plane either side out to define the rest of the tongue (see the blue and orange sketch in the image below).

    Also the swoosh above the cookie section and stripes on the vamp are now cut out, which you can easily replicated using simple Projected Split Lines.

  7. Step 7: Heel Counter Sculpt

    The tangency properties of a surface related to its intersecting surfaces and planes are always important to consider. The surface at the heel is not symmetrical in any way, only tangent at the Right Plane. Therefore we need to construct each horizontal section of this heel counter sculpt independently.

    First we split the surrounding area in which the heel sculpt will take place. Because we need tangency properties for each element to blend into the heel, we also make an additional split with an inner offset of the surrounding area curve. Then we split this section into horizontal bands so we have the sections we need to construct the boundary surfaces defining the ridges. On the Right Plane, we add the center V shape as a sketch for each boundary curve.

    After all Boundary Surfaces have been set up, knit them into the heel and round the transitions to end up with the following result.

  8. Step 8: Tongue Sculpt

    The molded sculpt on the tongue is a basic projection from the top. We are using guide sketches to build up the outline of the diamond shaped elements. These are projected onto the tongue as Split Lines. The resulting surfaces are copied using a 0.00 distance offset. Then these surfaces are thickened and finished using fillets, chamfers or Dome features, depending on your preferences. Lastly using Combine -> Add merge the resulting surfaces back to the tongue.

    This is starting to look like a shoe!

  9. Step 9: Sole Reinforcement Ribs

    Before adding studs, let's reinforce the sole with ribs. One rib goes along the entire front section into the heel at the inside, another one branches out into the center of the frontfoot.

    To create the first one, you can create an offset sketch based on the outline of the sole's bottom surface. To do so, start a new sketch on the 'P1 Top Pro' Plane created in Step 1, then select the sole outline and click 'Convert Entities'. Now select all converted entities and check the 'Construction Geometry' tick box. Then, use the Offset command to generate the new curve. You can also trim this with construction lines to create a partial offset as done in this case where the line needs to end before the heel section.

    Use the Projected Curve command to project the sketch to the sole surface. To create the rib, we will create a swept profile over the projected curve we created. First, create a plane based on the curve and one endpoint of the curve. This plane will be perpendicular to the curve so we can draw a profile. Draw a triangle with the approximate dimensions outlined in above image. Make sure the triangle sits just underneath the sole surface in order to be able to merge it. Also do not forget to Thicken the sole surface into a solid so we can merge it with the ribs in a later step.

    After also drawing the central rib in a similar way, to blend in the ends of the ribs with the sole surface we will employ an asymmetrical fillet on both sides of the ends which will come out great.

  10. Step 10: Studs

    With the ribs in place as above, we are going to create an exciting and challenging part of the shoe: the studs.

    For this step, we offset the sole's bottom surface and trim it with the sketch defining the studs.

    That results in the surfaces depicted above in purple.

    Three different offsets will make for three opportunities to create three different types of studs at different heights.

    The best way to do this would be to create each stud curve on a specific plane controlling the angle and resulting in an exact circle in order to mate with all-metal screw-in studs.

    Now having defined the stud outlines, create Ruled Surfaces with the option Tapered to Vector in order to merge them into the sole surface. You will need a vertical reference vector, or select the Top Plane.

    Now you will need to trim all studs at the top as well to be able to convert them into solids and merge them with the sole. After merging the solids, fillet all transitions, where possible using Curvature Continuous fillets. We will now also create the offset surfaces that we can use to cut the stud into the part blending into the sole and the overmolded or screw-in part using the Cut-Thicken command with a very small thickness.

    Now we also merge the ribs into the solid and fillet these to blend into the sole. Use another sketch and Cut-Thicken command to cut the sole into the two sections depicted below in black and green.

  11. Step 11: Heel Pattern

    For a final touch, let's add some dimples to the heel section based on a triangular grid.

    If our target surface was planar, the Fill Pattern would be a useful command.

    However now we need to first define the patch on which to create the pattern using a Split Line.

    Then using a sketched grid, create the Split Lines onto the patch that define the intersections on which to create the dimples. Then, create a 3D sketch and draw points on all the intersections (shown in blue in the image above).

    We need this 3D sketch as a base for the next command: Sketch-Driven Pattern. You will need to create a Revolved solid based on the tiny sketch depicted in blue above on the Right Plane behind the heel. This is the solid we will pattern onto every point of the newly created 3D Sketch. With all the orbs in place, cut these from the sole solid using Boolean-Subtract (or Difference in programs like Rhinoceros). Fillet the edges and we are done modeling our spectacular Adidas X18+ soccer cleat.