Maya Tutorial :: Lesson 7: Polygons vs. NURBS - Choosing Your 3D Building Blocks

Maya Tutorial ::.. Lesson 7_ Polygons and NURBS 

Alright, crew, strap in! We've built our temple and gotten our hands dirty with polygons. But now, it's time to answer a question that has puzzled new 3D artists for decades: what's the real difference between Polygons and NURBS?

Understanding MAYA Surface NURBS & Polygon Geometry Types | Mesh Types in Autodesk Maya \ Lesson-7

Think of it this way: if 3D modeling were carpentry, Polygons would be like working with Lego bricks—incredibly flexible, easy to stack and connect. NURBS, on the other hand, would be like working with a potter's wheel—perfect for creating smooth, flowing, and perfectly curved forms.

Both are essential. Both are powerful. And today, we're going to master both by creating a mini solar system. We'll learn not just how to create this geometry, but why we choose one type over the other.

The Great Debate: Polygons vs. NURBS

Let's clear up the confusion right from the start. You don't have to choose one forever. Professional artists use both, depending on the task. The key is understanding their strengths.

Polygons: The Digital Clay

We've already started with these, but let's recap. Polygons are a mesh of flat faces, edges, and vertices.

• Strengths: Unbeatable for hard-surface modeling (cars, weapons, buildings), organic character modeling, and is the absolute standard for video game assets.

• Weaknesses: A polygon sphere is only an approximation of a sphere. To make it perfectly smooth, you need a high number of polygons.

NURBS: The Mathematical Perfection

NURBS stands for Non-Uniform Rational B-Splines. Sounds complicated, right? Don't worry; the concept is simple.

• Strengths: Mathematically perfect, smooth surfaces. They are resolution-independent, meaning they remain perfectly smooth no matter how close you zoom in. Ideal for industrial design, car bodies, and any object requiring precision.

• Weaknesses: Can be trickier for complex, detailed shapes like character faces. They are also less intuitive for animation and are not used in real-time game engines.

In summary, use Polygons for almost everything in modern pipelines, especially characters and environments. Use NURBS when you need a perfectly smooth, precision surface from the start.

Project: Creating Our Cosmic Scene

The best way to learn is by doing. So, we're going to create a simple solar system. We'll use both geometry types and practice the crucial skill of precisely placing and naming our objects.

Step 1: Creating a NURBS Sun - The Heart of the System

We'll start with a NURBS sphere for our Sun because a star is a perfect, smooth sphere.

1. Create a NURBS Sphere: From the menu bar, go to Create > NURBS Primitives > Sphere. Now, instead of just clicking, click and drag on the grid to interactively place and size the sphere. For now, the exact location doesn't matter.

2. The Most Important Habit: Renaming! This is a non-negotiable professional practice. Look at the Channel Box on the right. You'll see nurbsSphere1 highlighted. This is the object's name.

   • Click in that field, type Sun, and press Enter.

   • Notice that Maya automatically updates the shape node to SunShape. This is how you keep a scene organized. Imagine a scene with 100 spheres named sphere1, sphere2... it would be a nightmare!

3. Precise Placement: The Sun should be at the center of our cosmic scene. We can do this with numerical precision. In the Channel Box, find the Translate fields:

   • Set Translate X to 0.

   • Set Translate Z to 0.

   • (We'll leave Translate Y at 0 as well). Your Sun is now perfectly centered at the origin of the 3D world.

4. Understanding Nodes: The Power of Inputs: This is a critical Maya concept. When you created the sphere by dragging, you set its position (handled by the transform node). However, its size was set by an input node.

   • In the Channel Box, look under the "INPUTS" section. You'll see makeNurbSphere1.

   • Click on it. The attributes below will change to show this node's parameters.

   • Find the Radius attribute and set it to 3. Boom! You've just precisely resized your Sun by editing its creation history.

Step 2: Introducing a Polygonal Planet - Earth

Now, let's create a planet. For this, we'll use a Polygon primitive to show the difference.

1. Create a Polygon Sphere: Go to Create > Polygon Primitives > Sphere. Click and drag to place it somewhere away from the Sun.

2. Rename and Organize: Just like before, go to the Channel Box and rename pSphere1 to Earth.

3. Positioning Earth: Let's place Earth a few units away from the Sun. In the Channel Box:

   • Set Translate X to 10.

   • Set Translate Y and Translate Z to 0.

4. Scaling the Polygon Way: With Earth selected, you won't see a "Radius" input like with the NURBS sphere. Instead, you scale it using the transform node.

   • Set Scale X, Scale Y, and Scale Z all to 0.7. This makes Earth smaller than the Sun.

Step 3: The Ultimate Test: Viewport Navigation

Now that we have objects in the scene, we need to be able to move around them effectively. Since these are the most common actions you'll perform, the keyboard shortcuts are essential.

• Tumble (Orbit): Hold Alt + Left Mouse Button and drag. Orbit around your Sun and Earth.

• Track (Pan): Hold Alt + Middle Mouse Button and drag. This moves your view without rotating.

• Dolly (Zoom): Hold Alt + Right Mouse Button and drag. Alternatively, just use your mouse's scroll wheel.

Practice this now! Zoom in close to the Earth polygon sphere. See the faint faceted lines? Those are the polygons. Now, zoom in close to the Sun NURBS sphere. Notice how it remains perfectly smooth? This is the core visual difference.

Node-Based Thinking: The Maya Superpower

Let's pause and talk about what you just did. You didn't just make spheres; you interacted with Maya's node-based architecture.

• The Transform Node (Sun, Earth): This handles where the object is in the world (Translate, Rotate, Scale).

• The Shape Node (SunShape, EarthShape): This defines the object's actual geometry.

• The Input Node (makeNurbSphere1): This is the history of how the object was created. You can go back and change parameters like Radius later!

Therefore, understanding that an object in Maya is often a chain of connected nodes is the key to unlocking the software's true power. It’s what makes Maya so non-destructive and flexible.

Your Mission: Expand the Solar System

Your homework is to build out this scene.

1. Create another polygon sphere, name it Mars, and place it at Translate X: 14.

2. Scale it to 0.5 on all axes.

3. Create a NURBS torus (Create > NURBS Primitives > Torus) to represent a ringed planet like Saturn. Name it RingedPlanet and place it at Translate X: 18.

4. Use the viewport navigation shortcuts to orbit your new mini solar system and admire your work.

Remember, the choice between Polygons and NURBS is a strategic one. Start with the end goal in mind, and you'll always know which digital clay to use.

---

Frequently Asked Questions (FAQs)

Q1: I can't find the INPUTS section in my Channel Box. Where is it?
A: It might be collapsed! Look for a small section header titled "INPUTS" below the main transform attributes. If you still can't see it, ensure you have the object selected and that you are in the standard Channel Box/Layer Editor layout. Sometimes, if you've deleted history (Edit > Delete by Type > History), the input node will be gone.

Q2: When should I delete history on an object?
A: Great question. You should delete history when you are sure you won't need to adjust the original creation parameters (like the Radius of a NURBS sphere) and before you do complex deformations. It keeps your scene clean and performant. The command is Edit > Delete by Type > History.

Q3: Can I convert a NURBS object to Polygons, and vice versa?
A: Yes, you can! Go to Modify > Convert. You can convert NURBS to Polygons and Polygons to Subdivs (another surface type). However, the conversion is not always perfect and can sometimes create messy geometry, so it's best to model in your intended final geometry type.

Q4: Why does my NURBS sphere look blocky in the viewport?
A: You're likely seeing the display precision. NURBS are always mathematically smooth, but the viewport approximates them for performance. To increase the smoothness, select the NURBS object, and in the Attribute Editor, look for the Tessellation settings and increase the display quality.

Q5: Where can I watch the video tutorial for this Polygons and NURBS lesson?
A: To see the solar system come to life and get a visual walkthrough of these crucial concepts, check out our detailed video lecture. For more tutorials, updates, and a community of learners, follow and support us on Facebook: https://www.facebook.com/drzeeshanacademy

Video Lecture

In this lesson we learn the basic difference between Polygon and NURBS geometry types. 

like us and Spread the word

https://www.facebook.com/drzeeshanacademy

Maya Video Training ::.. Lesson 7_ Polygons and... by zeeshanacademy