Crafting a quality 3D project often begins with meticulous planning. When it comes to 3D hand modeling, a well-thought-out strategy for your wireframe mesh is crucial. This planning phase should consider the model’s future requirements, particularly for animation and texturing, streamlining these processes before you even start modeling.
For a hand model specifically, paying close attention to creating geometry that complements the intended skeletal structure is paramount. Incorporating additional segments near joints is beneficial for maintaining joint definition during movements. Prioritizing a wireframe arrangement that minimizes creasing from skeletal deformations is also key. Issues like stretched textures, unnatural bone deformations, and unwanted creases can largely be avoided through proper planning and preparation in your 3D hand modeling workflow.
An effective planning technique involves using your own hand as a direct reference. If you possess a good eye for proportions and traditional drawing skills, sketching your hand from top and bottom views can be incredibly helpful. Add reference points and lines to these sketches to guide your 3D modeling process. For my approach, I opted to draw guide outlines and tick marks directly onto my hand, then scanned it to use as background images in Lightwave Modeler. If you find it useful, you can use the image provided below.
Figure 1: Hand Scan for 3D Modeling Reference
While I only scanned the bottom view, relying on my spatial reasoning for the sides and top, scanning additional views can be beneficial for more comprehensive planning. If you create your own scan, consider adjusting the contrast in Photoshop or similar software to ensure clarity. Converting the image to grayscale PNG is also advisable for optimal background image use in Lightwave or your chosen 3D modeling software.
To set your scan as a background image in Lightwave Modeler, access the display panel (d), navigate to the backdrop tab, and load your image from the image pulldown menu. Maintain the aspect ratio and adjust the size to approximately 210mm for a suitable scale.
With the palm’s basic outline established, we can proceed to model a finger. I chose the middle finger as it represents an average size, making it adaptable for creating the thumb and pinky later.
Add two points above the middle finger opening on your palm outline, around 2.5cm above the palm edge. Select all six points outlining the middle finger opening and create a polygon (p). Use smooth shift (F) or bevel (b) to extrude this polygon outwards, forming the finger’s length based on your background image. Employ the knife tool (K) to segment the finger into sections, using the tick marks on your reference scan as a guide for the number and placement of these divisions. Leave the fingertip as is for now. After some adjustments, your finger should resemble the image below.
Figure 2: Initial Finger Extrusion in 3D Hand Modeling
Extend the fingertip twice more using the bevel (b) or smooth shift (F) tools. Arrange the points as shown in the subsequent image, requiring some careful dragging for precise positioning.
Figure 3: Shaping the Fingertip in 3D Modeling
Subdivide the two polygons at the fingertip to create a pattern of four quads (Figure 4). Achieve this by creating two points (+), forming new polygons, and deleting the original nail bed polygons. Select these four new polygons and assign them a nail surface (q).
Figure 4: Creating the Nail Bed for a 3D Hand Model
Smooth shift the nail polygons once with a negative shift and positive inset (Figure 5), and then again with a positive shift and negative inset (Figure 6). Experiment with these settings to achieve a natural-looking nail shape. Fine-tuning with the drag tool (alt + t) can also be beneficial. Extend the topmost nail polygon forward to define the free edge or “French tip” of the nail.
Figure 5 & 6: Beveling Technique for Nail Formation in 3D Modeling
With the background image set up in your 3D modeling software, tracing the outline becomes the next step.
If your initial planning was detailed, tracing your wireframe from the scan will be straightforward. My reference scan included muscle contours and tick marks, but I needed to devise a polygon layout. To create the polygon pattern seen below, you can use various methods. One approach is to create points (+) at all intersections and then select sets of four points to form quads (p). Alternatively, you could experiment with the pen tool. I opted for the former method.
Figure 7: Tracing Polygons for the Palm in 3D Hand Modeling
Note the importance of maintaining a consistent number of points for each finger opening. This allows for efficient modification and reuse of the initial finger model for subsequent fingers. In this case, the index and pinky finger openings initially have one less point, which can be addressed later.
Also, observe the strategically placed triangle-shaped quads between the fingers. These are crucial for finger extrusion, increasing the edge count and providing sufficient geometry for the upcoming steps in 3D hand modeling.
With the palm and index finger base complete, we can clone the finger to create the remaining digits.
Select all geometry of the middle finger and copy it to a new layer. Repeat this process three more times. Starting with the second layer, set the background layer to layer 1. Using the existing hand geometry and background image as references, position the cloned finger in the index finger’s location. Stretch and rotate the finger to align with the new position, then refine its shape using the drag tool.
Figure 8: Positioning the Index Finger in 3D Modeling
Repeat this cloning, positioning, and tweaking process for the remaining fingers. Once positioned, weld all fingers to the palm. Ideally, each finger opening should have a matching number of points, simplifying the welding process. If not, you may need to perform additional polygon manipulation to seamlessly join them.
Figure 9: All Four Fingers Attached to the Palm in 3D Modeling
The knuckles represent a complex yet vital part of the hand. To model knuckles that appear realistic and animate effectively with bones, we’ll employ the spiderweb polygon pattern shown below. Create this polygon structure for one finger and then duplicate and adapt it for the others. Pay attention to the diamond-shaped quads placed between the fingers, which help to subtly represent the webbing between digits. Your completed knuckles and fingers should resemble Figure 10.
Figure 10: Detailed Knuckle Geometry in 3D Hand Modeling
With all four fingers modeled, we now focus on the thumb by developing the upper side of the hand.
First, extend the palm geometry upwards in two segments to meet the upper hand surface. Using point extender or a similar technique, extend the outer edge of the palm and drag these points upwards. Weld corresponding points and extend again. You should achieve a result similar to Figure 11.
Figure 11: Extending Palm Geometry for Thumb Creation in 3D Modeling
Next, begin extending from the knuckle edge backwards. These three additional segments will lead to the thumb area. Fill any gaps between the top and bottom surfaces to arrive at Figure 12.
Figure 12: Defining the Thumb Opening in 3D Hand Modeling
Now that the thumb opening is formed, we can repeat the cloning process used for the fingers to model the thumb. Modeling the thumb may require extra effort as it needs to be scaled and shaped significantly. After welding the thumb into place, your hand model should look like Figure 13.
Figure 13: Thumb Integrated into the 3D Hand Model
We’re nearing completion! With all five digits in place, only minor details and refinements remain.
Extend the existing geometry to flesh out the remaining upper hand surface. From there, extend further to define the wrist, resulting in Figure 14.
Figure 14: Adding Wrist Definition to the 3D Hand Model
The final stage involves meticulous tweaking. This is a critical step. Dedicate ample time to refine the geometry. Drag points, switch between polygon and subpatch modes, and carefully adjust the mesh. Thorough tweaking should lead to a satisfying final result.
Figure 15: Finished 3D Hand Model
Disclaimer: This tutorial outlines the process I used to create hands for my 3D characters. The technique is inspired by the foot modeling tutorial by rick suchy. I highly recommend checking out his work for further 3D modeling insights.
