> ## 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.

# Invalid Value

## Blend radius must be non-negative

### About the error

**Issue:**
The blend radius can’t be negative. That would create invalid geometry.

**Applies to:**

* Boolean Union
* Boolean Subtract
* Boolean Intersect

**Cause:**

* A negative blend value

**Solution:**

* Use a positive blend radius.

***

## Feature size must be greater than 0

### About the error

**Issue:**
The block can’t run if the feature size is zero or less.

**Applies to:**

* Mesh from Implicit Body V 1.0.0

**Cause:**

* The feature size is zero or less.

**Solution:**

* Enter a feature size that is greater than zero.

***

## The input mesh must be a quad mesh. Please use the Quadrangulate mesh block to convert

### About the error

**Issue:** Occurs when you are converting a mesh into a CAD Body. For this conversion to work, the input mesh needs to be a quad mesh.

**Applies to:**

* CAD Body from Quad Mesh.

**Cause:**

* A triangular mesh was used in the CAD Body from Mesh block.

**Solution:**

* Remove the triangular mesh from the input and convert it into a quad mesh using the Quadrangulate Mesh block. You may need to refine your quad mesh further to get optimal results. Review the process on how to create a CAD body [here](https://support.ntopology.com/hc/en-us/articles/360048784874).
  Make sure you are aware of the limitations of converting a mesh into a CAD body. This process is meant for topology optimized parts and not lattices.

* Related support articles for more information:
  * [Quadrangulate mesh fails when meshing my lattice](https://support.ntopology.com/hc/en-us/articles/1500000013521)
  * [What are the limitations of exporting lattice structures to CAD?](https://support.ntopology.com/hc/en-us/articles/360059299613)

***

## Cannot create a Voronoi lattice with \< 4 points

### About the error

**Issue:**
The mathematical Voronoi formula can’t be applied if there are less than four points.

**Applies to:**

* Surface Voronoi
* Volume Voronoi

**Cause:**

* Having less than four points.

**Solution:**

* Add more points to your Point List.

***

***

## R/G/B/A value must be between 0 and 1

### About the error

**Issue:**
The color channel value must be between 0 and 1, inclusive.

**Applies to:**

* Color

**Cause:**

* A color channel value that is negative or greater than 1 will cause this error.
* One common mistake is to enter color values in the range 0-255 without normalizing to 0-1.

**Solution:**

* Ensure color channel values are between 0 and 1, inclusive.
* If working with color values in the range 0-255, normalize by dividing by 255.

***