> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# nTop 4.0 - Cone Gradients Update

## Overview:

The purpose of this article is to explain the changes being made to the implicit body generated by the **Cone** block in nTop 4.0.

## Table of Contents

### [1. Effective Release](#h-01gyfxn1ynz1h7w3bcmb629x8a)

### [2. Change](#h-01gyfx6mmnpb8mpzymm25df6j5)

### [3. Impacted Blocks](#h-01gyfx6vgxsbh6jwcdq19ca0rt)

### [4. Example Differences](#h-01gyfx7e6d4bskcfvrqybf1efd)

### [5. How does this affect you?](#h-01gyfxk4ac45ynxqv0xxktaqeb)

### [6. Recommended Actions](#h-01gzcbd399z6qtve1k0m2k5gjy)

## 1. Effective Release

* nTop 4.0

## 2. Change

* In nTop 4.0, we released an improvement to the cone primitive. The implicit body produced by the **Cone** block now has numerically accurate field values when the cone is not oriented with the X/Y/Z axes.
* Because the previous result was incorrect in some cases, we did not version the block when implementing this change. In nTop 4.0, version 1.0.0 of the **Cone** block contains the bug fix.
* You do not have to manually update the block or change your nTop notebook to benefit from this fix.
* All previous notebooks that use the **Cone** block can still be opened and viewed in nTop 4.0+ and all future versions.
* Geometry that nTop caches on save, such as meshes, CAD Bodies, slices, analysis results, & more, will be available as view-only.
* If you re-run the **Cone** block, blocks downstream that use it as input will also re-run.
* Downstream blocks that utilize gradient calculations may produce a slightly different output.

## 3. Impacted Blocks

* The **Cone** block, version 1.0.0

Details on impact:

* We guarantee that operations that discretize your cone, such as **Mesh from Implicit Body**, **Voxel Grid from Implicit Body**, etc., are within your desired tolerance.
* You may observe differences in topology, for example, a mesh's element layout, vertex positions, and connectivity data.
* Since the numerical change is minor, these differences will often only be observed after two or more blocks downstream blocks, for example, **Mesh from Implicit Body** > **Remesh Surface.**

## 4. Example Differences

This section contains a few examples demonstrating the results from remeshing a cone between nTop version 3.45 and 4.0.

![Using a Remesh Surface block on a meshed cone in nTop 3.45.](https://files.learn.ntop.com/help-articles/backwards-compatibility-notices/16246865013267.png)

![Using a Remesh Surface block on a meshed cone in nTop 4.0.](https://files.learn.ntop.com/help-articles/backwards-compatibility-notices/16246848326419.png)

| Version                 | Edge Length (mm) | Face Count | Vertex Count |
| ----------------------- | ---------------- | ---------- | ------------ |
| nTop 3.45 (Top image)   | 0.5              | 3,038      | 1,521        |
| nTop 4.0 (Bottom image) | 0.5              | 2,846      | 1,425        |

##

## 5. How does this affect you?

As demonstrated in the previous section, the effect of this update on your existing workflows is minimal. You can expect a minor difference in the topology of a mesh or CAD Body generated from the **Cone** block, but this will not significantly affect any analysis, optimization, or downstream manufacturing processes.

## 6. Recommended Actions

Although we expect this update not to affect your existing workflows, we recommend that for any notebooks using the **Cone,** you either export and save any geometry prior to updating and/or save a copy of any notebook(s) with a different name before running the update to preserve your old results if needed.

## Keywords:

*update ntop change 4.0 cone gradients*