Throughout my CGI work, the scenes I create will be primarily populated with the building or product, but to set the scene props, landscapes, entourage, etc are added. These items, big or small have to be created and added to the 3D scenes.

Sometimes we use stock 3D models, which are very similar to stock photography. There are websites where you can download a wide variety of 3D models ranging from costing nowt, to hundreds of pounds. Once downloaded, the 3D models can be dropped into a virtual scene and used within the visualisation or animation.

With the majority of my projects I will 3D modelling various parts of a scene. In architectural visualisations I will model the buildings, landscape and other items, then populate the scene with stock library items such as cars and trees. I do this simply because the stock models available for foliage and vehicles is pretty extensive, and it would be counter-productive for me to start modelling these items, which could make the final cost of the CGIs too expensive for many. A collection of 10 cars can be purchased for a few hundred pounds, where as for myself to 3D model just one car would take at least a week, which makes a typical architectural visualisation just too expensive and time consuming.

Stock foliage used within a custom 3D modelled environment.

With interior visualisations and digital room sets, I find myself using less stock 3D model, in favour of hand creating custom items. My preference to do this has many factors.

1. Trends within interior design changes on a monthly basis, and as such many of the stock 3D items are dated, and have sometimes been created years ago. This is OK for the design classics, but for items that change with the seasons it's not ideal, and can really impact on the final image.
2. I can create almost any item in 3D, without it impacting on project costs or time too much. 3D modelling can be very tricky, and getting items to look realistic can also be hard, if not impossible for some, however when I started in the CGI industry over a decade ago (ouch), my speciality was 3D modelling, and doing it fast and good! Over the years I have continued to build on this core skill, evolving processes with every year, taking advantage of new techniques and software to be able to quickly create virtually anything.
3. Purchasing 3D models from stock sites isn't always straight forward, first you have to find the right model, at a good price (I am a Yorkshireman after all!), and then trust it's OK to use. Then once I've bought the models, approximately 50% of the time the 3D models will need adjustments such as re-scaling or fixing errors, and nearly every time I need to check the 3D model material finishes to be in-line with my techniques and processes. This can be time consuming, and could also become costly.
4. If I create the 3D models from scratch, I know the models are good, correct and error free. Maybe I'm not very trusting, or perhaps I just have faith in my own skills! Either way I know when I've 3D modelled an item that it's going to look good in the image, and if it doesn't look quite right, I know how to break it apart and improve it.
5. The final advantage of creating custom 3D items is that they belong to me! I will add items to my personal library for future use, and I will also re-sell the 3D models though my TurboSquid account to other folk. I must admit I don't receive much in the way of sales, but it pays for my dropbox account at least!

Franke sink and tap created from a handful of photos and dimensions.

A wire-frame shot showing the 3D construction.

Although creating the 3D models from scratch has it's advantages, it also has its disadvantages. Some items can be very difficult to re-create in 3D. Items such as cloth, plants, and other organic forms can be tricky, so much so that it's not uncommon for these type of items to be photographed in the studio, and super-imposed into the CGI in post-production. This is purely a time-saving technique, anything can be created in 3D, it's generally a matter of how much time is available to complete a job.

Dualit toaster, available to buy on TurboSquid

Other disadvantages could be that an items has little information or imagery to create an accurate 3D model. For example it's quite rare to find a piece of furniture photographed from every angle, instead usually the only reference is an angled photo, and generally the photograph will be of medium - low quality or resolution. So to create the furniture does require some educated guess work, and as such can't be too accurate. Clients will sometimes be able to physically send items to be turned into 3D models, which means a greater accuracy can be achieved, and is generally the only way to be certain of getting the 3D model just right.

Although I do find creating 3D models from scratch very useful, sometimes I do purchase 3D models. For interior room sets, I will often pick items from Design Connected, and occasionally TurboSquid and 90% of the time I'll be happy with the purchases. Purchasing these type of models will help speed up the process, which is very useful on projects where time is limited.

Both buying and creating 3D models has its advantages and disadvantages, and the majority of the time the decision to buy or make is made on a project by project case. As I've mentioned cost and time are two factors, however if possible I will always aim to use items I've created myself, this ultimately helps keep my work fresh, up to date and unique.

Dean