5D Virtual Constructions: Designer/Constructor’s

Perspective

Mohammed E. Haque* and Rajmohan Mishra†

* Texas A&M University/Department of Construction Science, College Station, Texas, USA, e-mail:

mhaque@tamu.edu† Texas A&M University/Department of Construction Science, College Station, Texas, USA, e-mail:

rajmohan@tamu.edu

Abstract— The construction activity level intricacy makes

the whole construction process quite complicated and

difficult for planners and builders. 4D (3D+Time)

construction planning is a promising area, and it presents

the ability to represent the construction process with the

additional sequential dimension. It makes the virtual

models easy to analyze and plan for the sequence of

activities. Traditionally, architectural/construction

engineering and technology education, especially

construction scheduling has been dependent on bar charts

and network diagrams. However, students can hardly

understand the schedule-construction progress relationship

using a CPM network or a bar chart. Using 4D visualization

students can learn time-space relationship in construction

schedule more effectively. The objective of this research was

to create a user-friendly 5D (3D+Time+Cost) model by

adding the cost of project with reference to the time line so

that the planners would be able to peg the cost control

measures with the schedule. The study provides a structured

method and a systematic approach that will enable the

students and planners to develop 5D models without

worrying about the errors and software hitches. This 5D

visualization model will facilitate developing a more realistic

approach to the whole construction process. The entire

model is integrated to produce an interactive visualization to

make the process fairly easier for students as well as the

construction industry professionals. In addition to this,

changes to the 5D model can be done easily by triggering

changes at one level. The techniques demonstrated through

5D virtual construction models can potentially be a valuable

tool not only in the classroom, but also as an effective

learner-centered self-directed tool to learn planning and

construction processes.

Keywords—4D/5D CAD, Construction Visualization,

Schedule Management, Cost Management, 3D Drawings

and Link System.

I. INTRODUCTION AND BACKGROUND

The activity level intricacy makes the whole construction process quite complicated and difficult for planners. The lack of tools for activity level visualization of construction projects presents problems to planners when considering the future implications of their decisions [1]. 4D/5D-Visualization is an emerging area and presents the ability to simulate the construction process with the additional temporal dimension, which makes the virtual model easy to analyze and plan for the sequence of activities. 4D/5D visualization facilitates minimizing re-work, which has the highest impact on profitability.

Nevertheless, owing to the interfacing among several software applications, the process of creating the 4D/5D model is often time consuming and it requires a definite skill-set to develop an effective 4D/5D model. The 4D visualization is widely adopted in industrial projects and has proven to be effective and useful. However, due to constraints in time and budget, 4D/5D-Visualization has not been quite accepted in the residential and commercial projects.

Significant research has been conducted in recent times on creating visualization simulating the techniques and construction process. 4D annotation and 4D models were developed [2] to help planners envision the quality of plans and identify potential problems during project planning. Simulation modeling and Virtual reality are also being increasingly used to help decision-makers make economically optimal decisions [3]. 4D visualization ceases to emphasize on the most important concern of planners i.e. the cost of project.

4D visualization has been contributing significantly to the industry and to the students as well [4]. Some universities have also included 4D visualization in the course curriculum. Different experiments were conducted with students as subject and the results evince that 4D visualization and virtual models have ability to analyze the schedule for potential conflicts. The recent works on 4D visualization has been categorized as per their intended applications.

Extensive research has been conducted recently to develop 4D models to help the construction planning in different ways. During the past decade, previous research efforts have been made towards advanced four-dimensional 4D planning models by adding the temporal dimension to the 3D animation model. Adjei-Kumi & Retik [1] developed 4D model using virtual reality (VR) technology to support practitioners to plan and visualize their plans. It proposes the use of a pre-prepared library of 3D graphical images of building components, facilities etc. and their related activities.

In the architecture, engineering and construction industries, computer visualization usage can cover the whole lifecycle of a product from presentation of initial concepts to the final stages of production and can also extend to maintenance issues. Three-dimensional models and subsequent virtual walk through animation can be created from hand drawn sketches, which can be conducive to the design process at the early stage [5]. Three-dimensional models can be used by design teams to communicate design intent to client and users, and to

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compare and evaluate design options. During more advanced stages of design, three-dimensional representations can be used to check the integrity of services coordination, accessibility and maintainability. During construction, visualization can facilitate the interpretation of design details by site operatives. Bouchlaghem et al. [5] reviewed the application of visualization in different process of project management such as concept design stage, design development and marketing of house building sector, and for modeling during construction stage.

Kang & Byeong-Cheol [6] presented a 4D model to detect the logical errors in a construction schedule and validated the same at Texas A&M university, college station experimenting on students on construction management. 4D visualization can be extensively conducive in construction education in a different ways such as complex analysis and structural design, soil mechanics, environmental engineering [7]. Students can understand the concept of project management through traditional lecture format teaching methods sometimes fall short of conveying the complex analysis and design principles that need to be mastered in structural design.

Further getting more into the 4D visualization, 5D or nD visualization can be more effective in linking cost, resources etc. to the 4D model to get more closure look at the project. 5D model steps forward and links different data sources to make the model more analytical. Further to this it creates an interface among all the project participants. However the 5D models have not yet fully accepted as the project management tool by most of the companies. The advantages are undoubtedly manifold. But the requirements and constraints like skill-set and time requirements prevail for most of the commercial and residential projects. 5D-visualization has not quite reached the industry as well as academia due to the complexity in developing 5D visualization models. Most of the 5D visualization software is not stand alone, so interface among the software often requires skilled employee and time to develop 4D/5D model. Time is the essence of any residential or commercial project. The time to bid is practically small even to prepare a satisfactory bid applying all the guidelines and best practices in estimation and planning. So allocating time to prepare 5D models seems to be practically not possible for most of the projects.

The aim of this research was to develop a 5D construction visualization model with reference to the time line so that the planners would be able to peg the cost control measures with the schedule and make more realistic approach to the whole construction process. The study emphasized on time-effectiveness of preparing a 5D model, which would be the key benefit for residential and commercial projects.

II. 5D MODEL DEVELOPMENT METHODOLOGY

The primary purpose of this study was to develop a framework to facilitate development of time-effective 5D models with use of software prevalent in the industry. The following applications were used in the study:

a. AutoCAD 2007

b. Google SketchUp PRO – Version 6

c. dxftocsv.exe (non-proprietary application)

d. Project 4D (P4D) from Common Point Inc.

e. MS Project 2003 or higher

f. MS Excel 2000 or higher

The P4D software application from Common Point Inc. classifies it as the most common software to create 4D models. It does not have the features of database interaction. However, it solves the primary purpose of the study to create 5D models for preliminary planning and bidding. Different 3D models were analyzed to find out the compatibility with P4D software.

The Google SketchUP is one of the most efficient software with excellent features to create 3D model in real quick time. The Revit from Autodesk is another excellent BIM application. But we did not intend to use the BIM features in this study. Google SketchUP has got limitations in exporting the layer information into the VRML file. But the 3D model from Google SketchUp can be exported as a .dwg file. The model can be opened in AutoCAD ready to export the model as a VRML file. P4D software has developed an application named as “CPTVRMLEXPORTER” to enable this feature. So the combination chosen is quite robust and infallible to bring the 3D model into the 5D environment. The framework for the 5D model discussed in the study is shown in Fig. 1.

3D Model 3D Model

5D Model

1.dxf

Cost EstimateSchedule

Geometrical Information

1.c

sv

1.dwg

1.w

rl

Fig. 1. 5D Visualization Model – Flow Diagram

MS Project has got the feature of linking with spreadsheet. For that reason, MS Project was chosen as the default application to create the schedule for the project. The linking of schedule activity and the relevant CAD component is quite cumbersome using the recommended procedure in P4D. So an innovative method was established to facilitate automatic linking of schedule activities with the relevant CAD components. It was found that the unique feature of the CAD components was their Handle IDs. So an application called “dxftocsv.exe” was used to extract the handle ID from the 3D model to incorporate the same to schedule activities. Once the schedule activities were imported to the 5D environment, they could be readily linked to schedule activity by using an automatic linking feature of P4D application. The cost estimate was prepared using the spreadsheet application from Microsoft. Cost estimate for preliminary planning

and bidding purposes involves reference to RS means manuals for historical data.

A. Extraction of geometric information from 3D model

The multi-purpose cost estimate was developed to get a quick estimate. The 3D model in AutoCAD was converted into a .dxf file. With the help of the dxftocsv.exe application geometric information was extracted from the 3D model and was saved in a file .csv automatically.

The application produced a Comma Separated Value (CSV) format file, which contained several geometrical information of the 3D model. Fig. 2 shows a screenshot of the dxf2csv.exe application window. Table I shows the .csv file extracted using the dxftocsv.exe application.

Fig. 2. Screenshot of dxftocsv.exe application

TABLE I.

EXTRACTED GEOMETRICAL INFORMATION (PARTIAL TABLE)

# Name Handle Layer

1 Group 13 1A4D7 Long grade beams

2 Group 22 1A4DB East side wall

3 Group 9 1A4DD Transverse Grade Beam

4 Group 77 1A4E5 North side wall

5 Group 51 1A4E9 Lintel

B. Construction schedule

The construction schedule was kept limited to only the Gant Chart preparation with inputs of detailed cost calculations. The procedure to prepare the construction schedule was quite generic. However, important steps incorporated to get the target 5D model is enlisted below.

Step 1: It is recommended that the schedule activities in the estimate be ordered in the sequence of their occurrence. This portion of the project has to be done manually. Automation on this portion leads to severe conflicts because of the complexity of the projects. After this step, the preparation of the schedule becomes very easy. MS project application has the functionality to link with spreadsheet application.

Step 2: Before proceeding with linking the cost estimate with the schedule, some columns are to be inserted in the MS project to receive information from the cost estimate. This makes the process of linking quite easier with direct column reference in the MS project.

C. 5D Modeling

P4D is a 4D modeling application, which has got capability to link 3D model with schedule activities. However, the standard procedure to link the activities is

quite cumbersome. The standard procedure is to link individual activities by dragging the same onto the relevant CAD components or vice-versa. This will make the process of changing the model extremely difficult, as we need to repeat the same process once again to link the activities with the cad components. So the process of automated linking was one of the primary contributions of this research.

This process of linking as demonstrated in Fig. 3 is quite cumbersome when we have to link large number of activities. Further to this, the corrections or modification of errors in 4D model or in the schedule, the same process of linking individually have to be incorporated to get the new 5D model.

To trouble shoot this problem or hindrance in preparing 5D model, it was found that the unique feature of the CAD components was their Handle IDs (Table I). So dxftocsv.exe application was utilized to extract the handle ID of CAD components and subsequently the same was incorporated in the schedule activities. By this process, the automated linking was established using the automate-linking feature from P4D application.

Fig. 3. Linking Procedure in P4D using Handle IDs

D. Cost Estimate in 5D Model

The cost estimate was incorporated in the model to get the breakup of individual cost estimate and the cumulative cost of all activities for a particular duration. The cost of individual activities was displayed in the “4D text overlay” feature of P4D application (Fig. 4).

E. Incorporation of changes

The model is ready to be changed any time with minimal effort to bring the same back to the 5D environment. The schedule activities and costs are loaded with the Handle IDs. So it will be easy to change the durations and relationships in activities without bothering about the linking with the CAD components.

Fig.4. Cost data on the 5D model

III. CONCLUDING REMARKS

This paper demonstrated a structured method and a systematic approach that would enable the students and planners to develop 5D models without worrying about the errors and software hitches. This 5D visualization model will facilitate developing a more realistic approach to the whole construction process. The entire 5D model was integrated to produce an interactive visualization to make the construction activities/processes fairly easier for students as well as the construction industry professionals. The main contribution of this study, such as automate linking procedure and preparation of time effective 5D model were achieved by analyzing the pros and cons associated with some available software applications. The model can be integrated into the academic classes to give student a perspective of the 5D visualization modeling. Currently, the model is limited to only preliminary planning as it lacks in establishing relationship with databases and / or servers. However, beyond the scope of this study further study can be conducted to find out methodology for linking of SQL server for integrating different data and information such as resources, craft-split analysis, craft requirement, lost-time accidents, cost of rework, weather report, delays and reasons etc. to prepare n-D models. These features can be incorporated by using Visual Basic application with database link to pull information and to prepare the project management model with capability of project monitoring. This study can be expanded to become a professional project management tool, which will be very conducive for the residential/commercial industry.

REFERENCES

[1] T. Adjei-Kumi and A. Retik, “A library-based 4D visualization of construction processes,” Proc., Information Visualization Conference, Institute of Electrical and Electronics Engineers,Piscataway: N.J., 1997.

[2] K. Mckinney, M. Fischer, and J. Kunz, “Visualization of Construction Planning Information,” Proc. of the 3rd international conference on intelligent user interfaces, pp. 135-138, 1998.

[3] V. R. Kamat and J. C. Martinez, “3D visualization of construction processes and products,” Construction informatics digital library,

Vol. W78, 2000. Retrieved Aug 15, 2006 from http://itc.scix.net/data/works/att/w78-2000-506.content.pdf.

[4] J. Messner, S. Yerrapathruni, A. Baratta, and V. Whisker, “Using virtual reality to improve construction engineering education,” Proc. of the American Society for Engineering Education, Annual Conference and Exposition, 2003.

[5] D. Bouchlaghem, H. Shang, J. Whyte, and A. Ganah, “Visualization in architecture, engineering and construction (AEC),” Automation in construction, vol. 14, No. 4, pp. 287-295, 2005.

[6] J. Kang, and L. Byeong-Cheol, “Impact of 4D visualization on the cognitive process of detecting the logical errors in the construction schedule,” ASEE Annual Conference & Exposition: staying in tune with engineering education, pp. 22-25, 2003.

[7] M.E. Haque, M.E., “Web-based visualization techniques for structural design education,” Proc. of the American Society for Engineering Education, Annual Conference and Exposition, 2001.