The Notebook Anatomy + nTop Interface

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Introduction

An example of the nTop interface Everything you do in nTop happens in the Notebook. This lesson takes it apart piece by piece — the interface that surrounds it, the sections and comments that organize it, and the blocks that fill it. Below is an example file that you can explore along with this lesson. Downloadable Files: Example File Download This file was last updated in nTop 5.54.2

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The Notebook & The Block System

A block is a function. It takes a set of inputs and computes an output. That output can then become an input to another block. The nTop Notebook is the collection of all the blocks in your file. The Notebook documents and represents an engineering workflow in nTop. It records all functions performed and captures a process that can be applied to any part, allowing users to reuse the workflow to generate new designs. An example of how the Sphere block correlates to the original equation for a Sphere Comparable to the model tree in traditional CAD software, the Notebook keeps a record of modeling operations. An nTop Notebook (left) compared to a traditional CAD feature tree (right) A feature tree records an ordered sequence of operations applied to a specific feature of geometry, while nTop Notebook defines a process that can be applied to any part. This distinction makes nTop workflows inherently reusable: the Notebook is what the engineer builds, and the geometry is what it produces for a given set of inputs.

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Inputs, outputs, and types

Every block produces an output with a specific type — such as an Implicit Body, Mesh, or Scalar Field(see nTop Block Types Image below). Types determine which blocks can connect: for example, an input expecting an Implicit Body will not accept a Mesh. Like types in programming languages, nTop prevents incompatible data from being connected. This helps:

• Ensure reliability: Use the right data in the right place.
• Prevent errors: Catch type mismatches immediately before they propagate downstream.
• Improve clarity**:** Colors and icons make data types easy to identify throughout the workflow.

nTop block types

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The nTop Interface

The numbered labels correspond to the nTop interface components below The image above shows the nTop User Interface. Use the accordion folders below to learn about the different components of the UI.

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Notebook Anatomy, Operations, & Best Practices

Your Notebook documents your work, and a little housekeeping goes a long way. Keeping it organized and commented helps with future use and sharing.

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1. Identifying the workflow

1. Notebook Name — Double-click ‘Untitled Notebook’ to name it. Use something unique and memorable, and match it to the file name.
2. Notebook Description — Double-click ‘Add description’ to write one. The description is what tells you, or a colleague, what the workflow accomplishes.

The Notebook Name and Description are located at the top of the notebook

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2. Adding, Placing, and Deleting Blocks

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Search Bar

As an alternative to using the ribbon, the search bar lets you quickly find a block when you know its name. Click it or press Ctrl + L, then start typing a block name. Results show the block color/type on the left and the block name beside it. Hovering provides the name, description, and Output type. The search bar displays all blocks relevant to the input text Alternatively, you can add blocks to the Notebook via the Ribbon. Click on block icons or select from the drop-down list in the Ribbon. Show/hide the Ribbon with Ctrl+D. You can navigate different sections of the Ribbon by clicking the tab names at the top bar

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Placement Highlight

The blue line indicates where you are in the Notebook. New blocks land at the Placement Highlight. Move this by hovering over blocks and selecting above or below them. Clicking between blocks changes the location of the Placement Highlight

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Search in Place

Right-click the dividing line between blocks to add a block, a section, or a comment at that exact spot. Double-clicking the line skips straight to the block search. Search in Place allows you to add a block at the Placement Highlight

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Context Search

Searches for blocks that are compatible with a block already in your Notebook, and nests your selection around it. Select a block and press S, or click the “+” icon on the block. In the GIF below, this functionality looks different when you make the block a Variable. We’ll cover Variables later in the lesson. Using Context Search on a non-variable block Using Context Search on a block variable

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Duplicating Blocks

This can be done with two methods: Duplicate and Duplicate with References

1. Duplicate – Makes a copy of the block and a copy of all blocks nested within that block. In this case, think of Duplicate as “copy block and nested blocks”. This is useful when you want to copy a block and change all parameters without links back to the original. To Duplicate, right-click a block and select Duplicate.

An example of using the Duplicate function in the right-click menu

2. Duplicate with References – Creates a copy of the top-level block while preserving references to its nested blocks. Changes to the referenced blocks update everywhere they are used. Use Duplicate with References when you want to modify the top-level block while keeping the same inputs. To Duplicate with References, right-click a block and select Duplicate with References.

An example of using the Duplicate with References function in the right-click menu The image above shows Duplicate with References applied to the top-level Extruded Cut block. The original block’s visibility is turned off, and changes to its referenced inputs automatically update the duplicated geometry. Both Duplicate and Duplicate with References create new blocks, so they should not be used as substitutes for Variables (more on variables to be covered later in this lesson).

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Cut, Copy, and Paste

Cut, Copy, and Paste move a single block or a multi-block selection through the clipboard. From the clipboard, blocks can be pasted into:

1. The Notebook
2. A compatible block input
3. A separate instance of nTop – a different Notebook

To select multiple blocks, hold the Ctrl key and select each block: You can multi-select blocks by holding the Ctrl key If the blocks you copied reference other blocks, use ‘Paste with References’ or Ctrl + Alt + V. It pastes all dependencies along with your selection, so nothing arrives with a broken reference. ‘Paste’ or Ctrl + V brings only the blocks you selected. These options live in the Edit menu, in the right-click menu on a block ‘Copy ’, and on the hotkeys Ctrl + X / Ctrl + C / Ctrl + V. Right-clicking a dividing line between blocks also offers ‘Paste’ and ‘Paste with References’, which lets you place the blocks exactly where you want them. You can copy blocks from one notebook to another using Copy and Paste

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Deleting Blocks

To remove a block, select it and then press the Delete key or right-click and select ‘Delete’ from the menu: An example of using the right-click menu to Delete a block

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3. Organizing

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Sections

Sections are the chapters of your engineering Notebook. Use them to organize your workflow into logical groups and give each a clear, descriptive name. Collapse sections you’re not working on to keep your Notebook organized and quickly navigate to the part of the workflow you want to modify.

1. Add a section with ’+ New Section’, located at the end of your Notebook

The New Section button appears after the last section in your Notebook

2. Collapse and expand a section using the chevron to the left of the section name

Collapse/Expand sections using the chevron icon next to their name

3. Rename a section by double-clicking its name.

Double-clicking a section name allows yout to edit it

4. Move a section by left-clicking on the right side of the section name and dragging. A blue line shows where it will land.

You can reorder sections by dragging them

5. Hover over a Section Name and select the three vertical dots to open the Section Menu, which holds ‘Add section’, ‘Move up’, ‘Move down’, ‘Rename section’, and ‘Delete’ section.

Open the Section Menu using the 3 dots icon

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Variables

You can make any block or parameter in the Notebook a Variable, making it easy to reuse and modify throughout your workflow. Variables remain visible in the Notebook rather than being nested within other blocks, helping keep workflows organized and easy to understand. A block made into a variable looks different from a regular block: its name appears on the left over the block color. To create one, right-click the block and select ‘Make Variable’. Double-click the Variable name to rename it. Creating a block variable and renaming it To make a parameter a Variable, hover over it, right-click, and select ‘Make Variable’. The new Variable appears above the block, while the original input is replaced by a Variable chip. A parameter Variable makes it easy to identify and quickly change a specific input within a block. You can also create variables from parameters Two additional operations that save time later:

• Hold Ctrl and drag a variable chip that is already in an input to reuse it in another input.

Ctrl dragging a variable input chip allows you to reuse it without removing it from the original input

• Right-click a variable and choose ‘Remove Variable Contents’ to empty it while leaving every chip in place. This is how you swap what a variable holds without rewiring the blocks that use it.

Using Remove Variable Contents to change the variable profile

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Input and Output Sections

The Input and Output sections are located at the top and bottom of your Notebook. They are primarily used to create Custom Blocks and run nTop automation workflows, both covered in later courses. The Input section defines the inputs to the Custom Block or workflow, while the Output section defines what it returns. To add a block or parameter variable to the Input section, right-click it and select Make Notebook Input, or drag it directly into the section. A demo of making inputs by dragging or using the right-click menu To define an output, drag the desired block into the Output section. Drag and drop your desired Output block into the Output Section

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Comments

A comment is a note attached to a block or placed in the Notebook. Click the speech bubble icon that appears when you hover above a block, right-click a dividing line between blocks, or open the Comment tab in Block Details (more on block details later in this lesson) to add a comment. You can attach comments directly to blocks or position them between blocks in the Notebook A few behaviors worth knowing:

• Block comments belong to the block. Move the block within the Notebook, and the comment moves with it. If a block is free standing in the notebook, it will not move unless dragged separately.
• If the block gets nested inside another block, its comment is nested as well, and an icon appears to indicate this.

Nested blocks with comments will have a speech bubble icon next to their visibility toggle

• Comments are searchable. Notebook search Ctrl + F filters on comment text, so a well-commented Notebook is navigable.

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4. Running and Checking

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Toggle Autorun + Manual Run Mode

1. Toggle Autorun – Controls whether blocks automatically rebuild when an input changes. When Autorun is on, a block rebuilds whenever one of its inputs or an upstream block changes. When Autorun is off, affected blocks wait until you run them manually or turn Autorun back on. Turn Autorun off when making a series of computationally expensive edits. Toggle Autorun is to the right of the search bar and can be toggled by clicking.

Toggling Autorun will compute all built blocks

2. Manual Run Mode – Controls whether blocks automatically rebuild when an input or any upstream block affecting them changes. With Manual Run Mode on, a run icon appears on affected blocks, letting you choose when to rebuild them. This is useful when testing a specific area or changing multiple inputs without spending computation time rebuilding downstream operations. To toggle Manual Run Mode for a block, right-click the block and select Manual Run Mode.

Manual Run Mode is helpful when you need to change multiple input values before you want a block to compute

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Rebuild Block

Reruns a block that failed, was canceled, or did not run because Toggle Autorun was off. Select the icon shown on the block below to rebuild it. Select the Icon to rebuild the block. The Rebuild Block button will appear next to the question mark icon

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Error Indicator and Error Log

A red icon in the Notebook’s top right corner means a block has an error. Select it to open the Error Log, which lists every error in the Notebook; clicking an entry navigates you to the block causing it. You can view the full error message by selecting the error in the Error Log

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Notebook Best Practices

Your Notebook documents your work. Months from now, you or a colleague should be able to open it and quickly understand what the workflow does, how it is organized, and what can be changed. A few simple habits make your Notebook easier to understand, maintain, and reuse.

• Name and describe your Notebook. Use a name that clearly communicates what the workflow does and matches the file name. Add a description that provides additional context. If the Notebook becomes a Custom Block, this description becomes the block description.
• Organize your workflow into Sections. Name Sections after the steps in your process. This lets someone understand the workflow structure before inspecting individual blocks.
• Comment where context is needed. You do not need to comment every block. Add comments where you made an important decision, assumption, or choice that may not be obvious later.
• Make important inputs Variables. Turn parameters that you expect to change into clearly named Variables so they are easy to find and adjust.
• Rename important blocks. Give key blocks meaningful Object Names that describe their role in the workflow. “outer_shell” is much easier to understand later than “Implicit Body_0”.
• Collapse what you are not using. Collapse blocks whose parameters don’t need to remain visible, and collapse completed Sections. This reduces clutter and makes the active parts of your workflow easier to scan.
• Not everything needs to be a Variable. Too many Variables can make a Notebook as difficult to understand as too few. As a general guideline, create a Variable when a value represents a design decision, is used in multiple locations, or may need to be modified when you reuse the workflow. Assign each Variable a clear, descriptive name. If a value is only an intermediate result, leave it nested and collapse the block.
• In Course 2, you will use Variables to parameterize relationships between geometry, allowing changes to automatically drive the rest of the workflow.

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Block Overview

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Output Types, Block Types, and Block Colors

Every block has an Output type and a block type. The Output type defines what the block produces and is indicated by its color. Block types are best distinguished by their colors and icons Output Types fall into six categories: Some categories contain subcategories, and each Output Type can include many block types. Because there are far more block types than Output types, color tells you what a block produces, while its icon identifies the block type. See the full list in block types in the nTop Product Documentation. Some blocks also support Overloads, meaning the same block can have multiple configurations and, in some cases, return different Output types. Blocks that support Overloads have a drop-down beside the Block Name for selecting a different configuration. For example, with the Add block, a user can select the following overloads for both inputs Operand A and Operand B. Below are the overloads for the Add block. Blocks that have one or several overloads available will have the chevron drop-down next to the block name You may also encounter Variants. A Variant is a block whose type can change based on the block, Variable, or value provided in the input. This allows the same input to accept multiple compatible types. In this example below, the same Box is a valid input for both an implicit body variable and a box variable. A Box block can be both a Box type and an Implicit Body type The Chevron Icon beside the Block Icon changes the Block Type. Use the chevron drop-down menu on the block icon to change the block type Together, Overloads and Variants let blocks adapt to different inputs and outputs, reducing the need for separate blocks that perform closely related operations.

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Block Anatomy

A labeled diagram of a block

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Three kinds of blocks look different from the rest:

• Variables: Their name appears on the left over the block color.

An example of a Box block variable

• List blocks carry a list icon over the Block Icon and show the list size in brackets after the name; add inputs with the ’+’ in the upper right, remove one with the ’-’ that appears when you hover. (More on working with Lists in Course 2)

An example of a block list

• Custom blocks have a double line down the left side, indicating a full workflow underneath. (More on working with Custom Blocks in Course 3)

Custom blocks have a double line symbol

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Block properties

Blocks carry more information than what appears in their inputs. Click the question mark icon on a block to open Block Details, which contains Properties and Comment tabs. We already covered Comments, so here we will focus on Properties. The Properties tab contains values the block computes automatically, such as a body’s bounding box or a mesh’s element count. Properties appear as chips that you can drag into another block’s input or expand to view nested properties. Clicking the question mark icon opens a block’s Properties Panel Properties help create parametric relationships. For example, instead of entering a fixed offset distance, you can drive it with a dimension from the geometry’s bounding box. As the geometry changes, the offset updates automatically. The simple example below shows a sphere’s center point updating automatically because it is driven by the cube’s Max Point property. Parameterizing blocks using block properties allows them to adapt as the design changes Dragging a property into the Notebook creates a Variable linked to its source block. In Course 2, we will use Variables and Block Properties together to parameterize relationships between geometry.

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Keyboard Shortcuts

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What to Take Away

• Treat the Notebook as a reusable engineering workflow, not simply a record of geometry creation.
• Give the Notebook a descriptive name that matches the file name, and add a brief description explaining its purpose.
• Organize blocks into clearly named Sections that reflect the workflow’s major stages.
• Use meaningful names for key blocks and Variables so their roles are immediately clear.
• Create Variables for important design inputs that will be reused or adjusted, while leaving intermediate values nested.
• Add comments to document important decisions, assumptions, or non-obvious logic. Comments are searchable and make the Notebook easier to navigate.
• Use Autorun and Manual Run Mode strategically to avoid unnecessary computation while making or testing expensive changes.
• Choose duplication and copy-and-paste methods carefully to preserve references and dependencies where needed.

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What’s Next

Now that you know how to navigate the Notebook, work with blocks, and inspect their outputs, the next lesson will look at one of the core ideas behind how nTop creates geometry: signed distance fields, or SDFs.