Assessment of 3D Geoportals of Cities According to CityGML Standard Guidelines

Comments

Explanation

1.      Although as I checked the internet sources, provided here, I found some mismatches, especially in Vilnius 3D mapping estimation. Please check it again, and I am attaching here along with the comments, the additional materials, that I have found about Vilnius city.

Corrected. The mentioned Vilnius 3D mapping format has been added and described.

2.      Some of the sources (like the Berlin city 3D map link) didn't have mentioned functions.

The studied geoportals are being developed and modified continuously. The investigation has been conducted accurately, howeverthe state of the services is current for the date indicated in the References section. The mentioned Berlin 3D map had been analyzed on 1 August 2022.

3.      This is only download portal without 3D map:

https://soest.virtualcitymap.de/#/

The portal provides the georeferenced 3D data, combining various data types (e.g. digital terrain model, textured 3D buildings model, orthomosaic) and providing some of the spatial data services, like visualization and downloading the content. Although it does not include a large scope of the facilities, it may be regarded as a 3D geoportal. 

4.      Diagram 1 Needs to be corrected

The diagram has been replaced by a clear table.

5.      The diversity is not a proof of the need, rather that technologies are quite new and are in experimental stage now.

The statement has been reformulated.

6.      these are already available in OpenStreetMap

OSM is a community project and thus its data may be not relevant enough.

7.      2D tracking is more practical in the meantime. Please prove that there are benefits from 3D tracking system then.

The aim of the statement is not to claim that the 3D tracking services are more practical than the 2D ones. The issue of its functionality is a broad topic. On the one hand, the 2D live maps provide a possibility of simultaneous tracking of any number of the objects or visual estimating of the distances between them. However, the 3D ones may be more suitable for the topographic orientation of the objects and they may be used e.g. for designing the augmented reality (AR) or virtual reality (VR) systems. The main point of the mentioned statement is that there is a reason to extend the city spatial data models by these facilities to integrate the different sources of data and improve the data accessibility andinteroperability. The tracking system data may be displayed both as a 2D dynamic map or in a form of a 3D model, depending on the choice of the user. This solution seems to be more practical than excluding the tracking systems from the 3D spatial data services.

Comments

Explanation

1.      Diagram 1 on page 6 is vague;

The diagram has been replaced by a more clear table.

2.      The visualization effect of article results needs to be improved;

The visualization of the results has been corrected.

3.      It is suggested that geological portal websites under investigation can be classified and displayed according to their characteristic information.

All of the spatial data services under investigation are the geoportals of the cities. The composition of the article provides the possibility of comparing the portals and its functionalities concerning the 3D urban spatial data. An additional thematic classification may be a topic of a different research, involving a larger number of geoportals and a larger thematic scope of the studied data.

Comments

Explanation

1.      Maybe some more metrics, like the user interface and navigation on the websites could have been added to the comparison.

The research concerned the tree-dimensional objects and the functions included in CityGML 3.0 standard. Thus, some of the other facilities, i.a. introduced by INSPIRE directive, have not been mentioned in the article.

2.      It also remained somewhat unclear to me, what the goal of the comparison is.

The aim of the comparison, as it has been mentioned in lines 86-91, is to assess the level of realization of the CityGML 3.0. assumptions on the example of selected 3D city geoportals and to evaluate the functionality of the studied portals in accordance with the criteria described in the article.

3.      Line 51: please introduce the BIM acronym

Corrected.

4.      Line 57: "marked in blue", where is this marking to be found?

Corrected. The sentence related to a figure which had been removed before.

5.      Line 119: please introduce the WMS acronym

Corrected.

6.      table 2: tunnels is a feature that is not present on any of the considered sites, this column could be eliminated from the table with a remark on this fact in the text, I think.

Corrected. The column has been removed. The information has been added.

Comments

Explanation

1.      The place names in Figure 2 on page 3 are a little fuzzy.

Corrected. The letters have been expanded and the linking lines have been added.

2.      The first two words in paragraph 2 on page 6 should be separated

Corrected.

3.      Check the overall formatting and writing of the paper.

Checked.