Introduction to Composite Imaging, 3d Modelling and Rendering and what part the photographer plays in the process

The images featured in this post are composite images made up of photography and CGI (computer generated graphics). A composite image is any image that is made up of different constituent parts and cannot be created with a camera alone. To create a composite you need a camera and a computer that has image editing software such as Photoshop. Many people new to photography can get disheartened when they see amazing images in magazines and on advertising bill boards because they believe these images were created by the photographer when the reality is they were created by a team of people made up of a photographer, image stylist and graphic designer/compositor and are rarely made up of one photographic exposure

The Creative Process and thinking behind composite image creation

The process for creating a composite image starts with a vision/idea that is sometimes sketched or roughly mocked up on a computer. This mock up is a visual aid the creative team use to determine how the shot will be put together (composited) and the constituent parts (elements or objects) they need to create the final image.

Most of us see composite images everyday on bill boards, posters and magazines. Take for instance an advertisement for Clinique Skin cream, you may see a picture of the product with water dripping from it or splashed all over it. The team who create this image know they need to supply the graphic designer, who will ultimately make the composite image using his computer, with 2 constituent parts, Water and a quality photograph of a tub of Clinique Skin cream. The graphic designer/compositor then uses his skills and the original idea/vision to create the final image. Many people who see images like this believe the photographer spent many hours throwing water at the tub of moisturiser and then pressed the camera shutter at just the right time to create the beautiful image, but this is not the case. In actual fact the photographer either photographed each part separately and then supplied them to the graphic designer as 2 separate image files or the photographer photographed one part of the image and then the graphic designer found the other constituent part on an image library on the internet or some other source of images.

Compositing images with CGI (computer generated graphics)

Advertising agencies and photographers have been creating composite images for many years but until recently the process did involve photographing each part of the image separately. But now with modern computer power and software we can create many of these constituent parts from scratch.

The images featured here are made up of the following elements

3d Models (the large pistons)
Photography (the People)
3d Rendering (the process of making the 3d models look realistic)
The Graphic Design image composting

To help you to understand how each part was created here is an explanation of the process

What is 3d Modeling

In three dimensional computer graphics, 3D modeling is the procedure of developing a 3D model using specialized software. It is a process of creating a wireframe model that represents a three dimensional object. That object can be alive or inanimate. A three dimensional model is created using a set of points in 3D space, which are connected by various geometric data such as lines, and curved surfaces.

Polygonal modeling. Many three dimensional models are created as textured polygonal models. Polygonal modeling is a method of creating a 3D model by connecting line segments through points in a 3D space. These points in space are also known as vertices. Polygonal models are very flexible and can be rendered by a computer very quickly. One cannot, however, create an exact curved surface using polygonal 3D modeling technique.

Primitive modeling. This is the simplest way of modeling three dimensional objects. Using geometric primitives such as cylinders, cones, cubes and balls, complex models are created. This approach ensures easy construction as the forms are mathematically defined and precise. Primitive modeling is mainly used in developing 3D models of technical applications.

NURBS modeling. The NURBS (Non-uniform rational B-spline) modeling method can be found in popular software like Maya. The developer can create smooth-surfaced 3D models using this modeling technique. Unlike polygonal modeling techniques which can only approximate curved surfaces using numerous polygons, NURBs modeling can truly create smooth curved surfaces.

Photography – Shooting images to make compositing easy

The photographic part of the process (the part I playing in creating these images) involves shooting images that are easy to extract from the background. Photographers often shoot against pure white background or single colour backgrounds because this makes it easy to extract the subject from the background. The people who feature in this image were photographed against a pure white background and instructed to pretend they were holding, cleaning, inspecting or carrying objects above their heads.

What is 3D Rendering

3D rendering is a creative process that is similar to photography or cinematography, because you are lighting and staging scenes and producing images. Unlike regular photography, however, the scenes being photographed are imaginary, and everything appearing in a 3D rendering needs to be created (or re-created) in the computer before it can be rendered. This is a lot of work, but allows for an almost infinite amount of creative control over what appears in the scene, and how it is depicted.

The three-dimensional data that is depicted could be a complete scene including geometric models of different three dimensional objects, buildings, landscapes, and animated characters – artists need to create this scene by Modelling and Animating before the Rendering can be done. The 3D rendering process depicts this three-dimensional scene as a picture, taken from a specified location and perspective. The rendering could add the simulation of realistic lighting, shadows, atmosphere, colour, texture, and optical effects such as the refraction of light or motion-blur seen on moving objects – or the rendering might not be realistic at all, and could be designed to appear as a painting or abstract image.

Putting it all Together in Photoshop

This is the job of the Graphic designer or compositor as they are sometimes known. In this example the graphic designer was supplied with hundreds of photographs of people pretending to carry, hold, inspect or clean objects. They are also supplied with the 3d Models fully rendered. The process of compositing the images together involves extracting the people from the background and then placing them in the scene at the right position, size and perspective to ensure they look realistic with the image frame. The designer also has to ensure the lighting and shadows are consistent throughout the image

Summary

I hope this has helped you to understand the process of high level commercial imaging. The images that you see in the press and on television are rarely created by one person and the skills that contribute to making these images are easily attained through hard work, practice and study.

Commercial Photography Creating Composite Images using Photography and CGI