# Validating Surfaces

- Introduction

The best* way* to generate surfaces is

**by using a topography surface created by MiningMath,**which is created after the Data Validation, then

*. Make sure to*

**manipulating only the Z coordinates****meet all the surface requirements**disclosed here.

### Surface Requirements

**Headers**must be named as X, Y, and Z. These files have to**obey an ascending value order**in each one of the axes.**Same size of the block model**,*item 1.1*of this page explains it*.*Its

**points must be aligned with blocks' centroids**,*items 1.1*and*1.2*help you to understand it*.*Defined as a

**grid of points**,*the visual validation, item 1.2 shows it.*To be in the

**CSV format**.

Figure 1: Surface file format of MiningMath

## 1.1. Surface and Block Model boundaries

By using the values of a Marvin Deposit file in *Figure 2, ***we find the Block model ****centroids boundaries** which begin at **XMin=15; YMin=15 and has the maximum centroid value** of **XMax=5,295**; **YMax**=**8,265**, which could be confirmed by checking the topography generated by MiningMath.

Then, its time to** search for** **your surface limits, **at this example the file chosen was *"Surface-RM-offset-300m".* The easy way to find it, is by filtering the axis values, as shown in *Figure 3,* which disclosed **XMin= 15; YMin=15** and** ****XMax= 1,815** and** YMax= 1,785. **Therefore, **even though this file was also based on Marvin Deposit**, it is not possible to use it since **the surface smaller than the block model in place**, which means that it does not have the same size as the block model file.

It is always worthwhile to **check the limits of the designed surface ***(Figures 4 to 8)*** **if we face an error. Remember that **everything, **even elevations, **must be in the boundaries **of the block model and check the recommendations for your surface.

**Correct Surface**(grid of points)

**aligned with the centroids**and

**same block model size.**

*Maximum boundaries formula*

*Maximum boundaries formula*

The **centroids** **maximum limit **by using the equation for each axis:

**Maximum centroid value = OX + (NX*DX)-(DX/2)**

Where:

OX is the origin in the X-axis;

DX is the block dimension in the X-axis;

NX is the number of blocks in the X-axis.

**Note: ***(DX/2) is related to the distance which should be summed on the origin to find the centroid of the first block, or reduced at the block model limit to find the last centroid, since origins are based on the corner of the block model.*

## 1.2 Numeric and visual validation

The following video presents how to validate surfaces numerically and visually. This initial verification is what enables you to understand what might be happening and where the error is. The example used regards to the message: * "Error parsing surface: Coordinates aren't properly spaced"* but it fits any case where the surfaces used are causing a problem, especially when a

*shows up.*

**red box error**In this case, as there are a lot of values that do not match the correct ones for X and Y, the * quicker and easier way* to fix it is restarting from the beginning.