Field guide
Inspect a terrain delivery before using it
Review the supported objects and their limits before handing data onward.
What this file review helps you decide
A LandXML viewer is useful when a design arrives as an XML attachment and you need to know what can actually be handed to the next person. The extension alone does not tell you whether the document contains survey points, a complete triangulated surface, or only the ingredients used to create one. Start by reading its object list, declared units and record counts. Then select the particular point group or surface relevant to your task.
This page reads the supported content locally in your browser. It does not send the file to a conversion service. Its purpose is to expose a practical subset of the document, identify problems in that subset and extract traceable records. A successful preview does not establish that a design has been approved, that its reference matches your project, or that a machine controller will accept it.
Keep the version and scope visible
The reader accepts LandXML 1.1 and 1.2 with the corresponding standard namespace. It accepts direct CgPoints groups and surfaces with a TIN Definition containing explicit Pnts and Faces. Other document sections are listed as uninterpreted. A file with only alignments, parcels, observations or proprietary extensions may therefore contain useful information that this tool does not draw or convert.
This is a structural check of supported records, not complete validation against every rule of an XML schema. The reader does not fetch schema locations, resolve external entities, load referenced projects or rebuild proprietary surface history. Keep the original file and its delivery notes. The JSON report retains that original text so a later review can inspect content outside the supported subset.
Read northing, easting and height deliberately
For the supported LandXML coordinate records, the text order is northing, easting and elevation. The extracted point table deliberately labels its columns Point, Easting, Northing, Elevation, Description, Code and SourceRecord. That difference is a column arrangement, not a coordinate transformation. Compare a known control point with the delivery documentation before sending the table onward.
Point identifiers remain strings, including leading zeros in a CgPoint name. Descriptions and codes remain separate fields rather than one replacing the other. Two-dimensional CgPoints can retain a blank height, but a TIN vertex needs all three coordinate components. Missing height is not automatically set to zero. Original numeric text is preserved in the point exports; the preview uses numeric values only for drawing.
Units are part of the handoff
The summary displays the declared linear unit and preserves the unit attributes in the report. Metres, international feet and US survey feet are recognized for the surface-query workflow. Missing, conflicting or other unit declarations do not silently become metres. You may inspect retained raw records, but the next calculation is unavailable when the supported unit cannot be established.
Write the horizontal reference, vertical datum, project revision and intended use in the reference field. A unit label alone cannot distinguish a local site grid from a national projection. The viewer does not apply a map projection, a datum shift, a geoid model or a unit conversion. If a source uses different height units, prepare a consistent file in the originating software and verify it before querying.
A surface contains connectivity, not just points
A TIN is defined by both its vertices and its triangle references. Exporting the vertices to CSV is useful for point inspection, but triangulating those points again can create different edges, connect a gap or change a slope break. This page therefore never rebuilds the mesh and never describes a point-only export as an unchanged surface.
The face audit keeps the original face record number, three referenced point identifiers, visibility flag, attributes and any detected error. Use it alongside the point table when reviewing connectivity. To continue with the design-elevation tool, use the surface button: it transfers the original XML and selected object, allowing the receiving tool to read the same triangles again.
Understand visible faces and gaps
A face marked with i="1" is retained in the audit but excluded from the active surface. Such records may represent areas that should not participate in the physical surface. Missing active triangles also leave areas where an elevation cannot be interpolated. A rectangular coordinate extent does not mean every location inside it has surface coverage.
Supported explicit outer and hide boundaries use one direct coordinate list per ring. Invalid, self-crossing or unsupported boundary definitions prevent elevation queries. Breaklines and contours in source data are not reprocessed to invent new faces. When you need a reliable triangle delivery, request a current export with the intended trimming already reflected in its triangle definition, and compare it with the source application.
Review errors before extracting a point set
The checker retains duplicate point identifiers instead of overwriting an earlier record. It also checks coordinate values, triangle reference counts, missing referenced vertices, repeated active triangles, degenerate triangles, duplicate horizontal vertex positions and edges shared by more than two active faces. A mixed winding direction is reported without reversing the original records.
Point errors block point extraction for the selected object. A triangle problem can block surface queries while still allowing an otherwise valid vertex list to be extracted after review. That distinction is useful when returning a damaged delivery to its author. It does not mean the vertex list repairs the surface. The report explains the object and record associated with each detected issue.
Use the plan view as a navigation aid
The preview draws the original active triangles in a plan view with east to the right and north upward. It is not a satellite map, a perspective rendering or proof of a coordinate reference. Click a displayed point, or use the arrow keys, to move to the associated table page. Read the numeric record when an apparent point location is uncertain.
The drawing shows at most 15,000 triangles and 1,500 point markers to keep interaction manageable. The table is paginated, and exports use the complete selected object. A dense preview can hide narrow gaps or overlapping edges, so do not treat its appearance as a whole-mesh topology certificate. The next tool checks all candidate faces at each requested location.
Choose an export that answers the next task
Use point CSV for another surveying application, XLSX for spreadsheet review, and the face audit for connectivity questions. The workbook export stores values as text to preserve identifiers and original decimal strings. If you later convert spreadsheet columns to numbers, choose that operation deliberately and recheck any leading zeros or long decimals.
The complete JSON is the audit package. It includes the original XML, object records, issues, metadata, selected object and your reference note. Unsupported content is retained in the original text rather than silently converted into approximate geometry. Neither the point table nor the face audit is a newly certified LandXML file; return to the source application when an edited surface must be published.
Work within clear file limits
Upload UTF-8 text up to 10 MiB, with at most 100,000 points and 200,000 faces across 100 supported objects. XML depth and complexity are also limited. Large sources show a shortened read-only text preview while processing the complete retained input. The cancel button stops the background work, and restoring the original text lets you repeat a review after an edit.
Clear the session when finished. Between-tool transfers use a short-lived local browser channel and require the source tab to stay open until receipt. No coordinate values are placed in the URL or persistent storage by that transfer. Keep downloaded audit files according to your own project procedures; clearing the page does not erase files you deliberately saved.