QTO Workbook Weights

[AdvancedCM]

I performed a Revit model takeoff which captured the structural framing elements in my workbook but there were no weights for the steel objects even though the Unit Weight in Revit Material property in Navisworks is 490.00 lb/cubic ft and the Volume property in the element tab is .4975 cubic ft for one object which does show up in the workbook. Does anyone know why Navisworks wouldn't calculate the total weight of that object?

I guess I could create a formula in the exported Excel file but this seems strange.

[OR_AND_NO]

You are right NW have to do it, but you should write Weight expression (Weight=UnitWeight*Volume) in the Item definition in QT. Ufnfortunately I cant just now to find in YT the lesson how to do it. Since my work comp far from me now I cant make screen copy to clear.

[AdvancedCM]

Thanks; good point, however while the property tab for Revit material has the Unit Weight per cubic foot the ModelWeight column in the QTO workbook is blank. So any volume x ModelWeight will end up being zero. You can manually enter the ModelWeight in the workbook but that defeats the value of QTO automatically calculating a specific model weight per object.

I think QTO isn't picking up the unit weight property from the property tab for the structural object in the workbook. If the unit weight was in the workbook your explanation would work but I would expect not having to write weight formulas in QTO for every project. This type of formula should be built in using the correct model element properties.

[OR_AND_NO]

Could you attach a small example revit file here?

[AdvancedCM]

I can't share the file I'm using but you can go to the sample project at the URL below. It displays the same problem. Select the structural framing wide flange and you will see that the Model Weight column is blank yet the Unit Weight in the Revit Material tab is 77.0 kN/m³.

This problem shows in Navisworks 2017 and 2018.

https://knowledge.autodesk.com/support/revit-products/getting-started/caas/CloudHelp/cloudhelp/2016/...

[OR_AND_NO]

Unfortunatlly I've seen 0.0 kN/m3 in material property in one of your refference and not seen Weight parameter in structural element (column). It is possible to create Weight parameter and calculate it using volume and right unit weight.

[AdvancedCM]

Using Autodesk’s own Revit sample from the link above the model weight still doesn’t work. Industry standard commercial shapes for this particular wide flange should be 19 lbs/ft which I’d expect to be a standard Revit property. Even though Navisworks should be able to calculate the model weight from the internal property values and the proper formulas I would not expect I would have to create special formulas to accomplish an industry standard quantity takeoff property.

In fact I did attempt to map the model weight field to the unit weight field yet nothing changed. This is not a very well thought out feature of Navisworks. Estimators don’t have the time to write formulas for every model file instance when industry standard data is available with other software.

[AdvancedCM]

Well, after much research into how Navisworks sets up the project workbook by reading the takeoff map I've discovered there is no mapping for a weight parameter in the standard issued xml file. All other parameters exist other than weight. So now I'm off to figure out how to modify the xml file to calculate model object weight.

[OR_AND_NO]

To get unitweight in navisworks from revit file you have to store project unit in revit project without letters (see r_0.png picture) 

After load revit project in navisworks and map revit properties to qt model properties as shown on picture n_1.png.

Calculate weight as shown in picture n_2.png and result will be like in n_3.png.

[OR_AND_NO]

I am sorry since I can't set eng language in NW, so perhaps you are surprised by kirilic symbols 🙂

To somehow avoid it I give you here very short en-ru dictionary: Weight=Вес, Volume=Объем, Model=Модель.

And attached n_3.png.

I hope it helps you.

[AdvancedCM]

Thanks. But that still is a major problem. Often folks do not have access to the native Revit files or can dictate to the design professionals how the Revit parameters must be set. So requiring no unit names for the unit weight field by the designer is an epic Autodesk fail.

After working with the TakeoffPropertyMap1.xml file and noticing it doesn’t contain any weight mapping I’ve also discovered other defects. It seems that QTO only pulls property data from the Revit Material tab data as also demonstrated in your examples in Navisworks and not any data from the Revit Type tab even though there is xml code for that tab. In fact in the Revit Type tab field W contains structural weights per foot (with no unit names to cause problems like you describe, I might add) which is in alignment with dimensions and section properties in industry standard tables. Second Autodesk fail.

Thanks for you work and time but in my opinion the QTO feature of Navisworks is so immature based upon their own property parameters and industry standards that it’s best to avoid using this feature. That’s what I’m going to do.

[OR_AND_NO]

I believe that it is possible to define Weight in TakeoffPropertyMap1.xml. I've seen in YouTube an example with same Rebar lenht definition.

Of course Revit and NavisWorks are not perfect and may be far from perfect.

But they have power APIs that help to customize them to customers needs and our group use API to customize these tools for own needs.

Our group deep working by BIM technology for only couple years, but almost all projects we manage from design to build, so now we already know what parameters we will need at last phases of process and define ones already at start. In other words we have own draft BIM-standard that helps us to work in group or with third party for life time of project development.

What tools are better in your opinion?

[patrick.beattie]

Hi @AdvancedCM,

I wanted to reach out with regards to this forum post.  I understand that you are trying to get Revit Material properties into Navisworks.  

I can see that you are aware of the ability to map the properties and then wright an expression to calculate the Weight from the Unit Weight and Volume.    Even with the expression, it doesn't appear that the Unit Weights are automatically coming through.  

I'm going to reach out to my colleagues to see if they can provide further insight into getting the Revit Unit Weight properties into Navisworks so that you can calculate the weight.   I'll provide another update with the information that I discover.  

Feel free to reply to this forum post with any additional questions or comments.

Best regards,

[patrick.beattie]

Hi @AdvancedCM,

I'm following up with regards to this forum post.  To calculate the total weight of an object when the property contains Units, you will need to export to Excel and use formulas to manipulate the data.  When a property is mapped with units, it is taken as a string of letters instead of numbers.  

You can map to the Takeoff property Description1, export to Microsoft Excel, and then manipulate the cells to remove the letters and calculate the total weight.  I put together the article Navisworks Manage: Using Quantification and Excel formulas to manipulate data that explains how you can get the weight calculation within Excel.  Within that article there is a video that I created that is also available in the Community Screencasts under Using Quantification and Excel formulas to manipulate data.

If you would like to submit feedback for Navisworks improvements to the Quantification area, I strongly encourage you to submit to the Autodesk Product Feedback page.  The information submitted there will be reviewed by the Product Team.

Please let me know if you have any questions or comments with the information provided.  If you consider this post resolved, please choose Accept as Solution on the post you find helped the most.

Best regards,

[Alfredo_Medina]

@patrick.beattie , @AdvancedCM

This is indeed disappointing. The relationship between the UnitWeight propertiy of a material in Revit and the "=ModelWeight" property in Navisworks is broken. Even if the mapping of these two properties is done correctly, Navisworks does not report the weight. The only way it works is if the user goes to the Item Mapping Rules and edits =ModelWeight to be, for example: ModelVolume * 10 ... (or any other number). Then Navisworks shows a result. But that means that if I have 100 different elements for which I have to take-off their weight, I have to manually edit the properties of each of those items in order to take a result, which, I agree, defeats the purpose of having an application that is supposed to read properties from the model to produce quantities. Are there any updates on this issue? I am using Navisworks Manage 2018.