Documenting building render accuracy

[Karin Skaug]

As a client of ours is deploying quality control of renders, another company has been caught cheating in their 3d-illustrations.

We are now asked to describe how we arrive at the representation of the new buildings and document their accuracy compared to the existing surroundings.

(This is regarding photomontages with a rendered project composited against a photo background.)

 

Have any of the users here been asked to document the accuracy of you renders?

How do you - in that case- do it?

 

(It is a timely, yet strange idea to quality check cg-illustrations, but as they often are delivered as a representation of a "future truth", is is a reasonable question.

I just wonder how they do the actual checking, as there is so many software packages and different workflows involved in producing this kind of imagery)

[harryhirsch]

never heard of such a case...but this is no surprise...some investors or citizens do not like the building, they compare it to the rendering and say ''hey, the building does'nt not look 100% like the rendering- now we sue the architect''. ... how to proof your accuracy? I would document the working process (Screenshots) ...the import of clients DWG files, the modeling of the environment/background according to the siteplan/DWG etc. I would not submit dwg files to anyone...and I would update my contracts (that I provide renderings according to given files, that photomontages /backgrounds represent an idea but are not accurate...)

[Devin Johnston]

People tend to believe what they see in a rendering and the expectation is that their project will end up looking like that. If you don't educate your client you could be in for some problems so I always make it clear that a rendering is only a representation of what a project may look like. I've never heard of a client wanting accuracy in a rendering beyond having the exact materials and furniture that will be in the final project. It sound to me like they are basing all design decisions on the renderings and that can be a mistake. I can see how you could document a project but it would be extremely time consuming and probably not worth what there paying to have the rendering done. If I had a client like this I think I'd pass on the project, some people are just too difficult to work with.

[John Dollus]

It's not so much of an issue in the US but other countries place more emphasis on the verifiable accuracy.

 

Great article regarding the 'optimistic' nature of renderings compared to reality:

http://news.nationalpost.com/news/canada/architectural-illustrators-use-toolbox-of-tricks-to-manipulate-the-way-we-look-at-buildings

[Francisco Penaloza]

Well I have done a few "survey" type of renderings and light studies before, and like always everything start from a good talk with the client and set some common rules and expectations.

 

If your client need to go all reality in the project, you need to make him understand, that the final image won't look all flashy and sexy.

Then you just ask for, surveys, CAD drawings, Revit files and what not, and just follow those. Keep everything up to scale 1:1.

If it is possible use IES for everything, Sun light system with the correct geographical location and adjust exposure on the rendering. Try to avoid using curves and maybe a little or color mapping.

 

If you are doing photo match, you need to have all the info of that shot, location, position and orientation, time of the day, year, month, camera specs, lens size.

 

Most of the time the renders come flatter of what 'we' usually do, but other than that they get pretty close to the real thing.

 

Lighting is the most difficult part, because, your client needs to understand that your image is a representation of what a photo camera will see and not what a human eye will see. Of course you can adjust either to match, but then, you are working with interpretation and not physical accuracy.

 

If you follow all basic rules you can get pretty close, remember that even while they are building the project they need to do adjustment and not always can be build as planned.

 

I remember Jaime Cardoso (sometimes pop up here in the forum) he did a very good writing about similar projects.

You may want to check his blog.

http://jamiecardoso-mentalray.blogspot.com/

 

Be sure to put in your contract, as mentioned by Davin, that you are not liable for the accuracy of the images that were produced with the CAD data that was given to you. If the CAD are OK, then you are OK.

 

Best luck.

[Karin Skaug]

Thank you for helpful answers.

I also got a very helpful reply from Des in Ireland on the formZ forum on this topic:

http://forums.formz.com/index.php?/topic/3955-documenting-building-render-accuracy/?p=14350