Render mode allows Blender to perceive light sources, shadows and reflections. Knowledge of cinematography is needed as the programme has been made to duplicate real life conditions.
Object mode is purely for modelling. It takes the least amount of CPU to run and it is where a model can be be shaped and created in the most simplest fashion.
Creating a 3d world around a model
This is a fairly dated process where you attempt to build a world using flats which are then textured to give out light emission. The obvious problem here is that a 3d world or ‘hemisphere’ is not box shaped but either dome shaped or spherical. This same process will apply to a spherical design although the process is difficult with lots of room for faults and tears in texture.
The design here shows the use of two different lighting techniques; one being a white emission given from the flats above which act as our fluorescent light; the other being the emission from uploaded images. As our 3D model has been set to ‘gloss’ it will reflect light from outside sources. The use of nodes can also intensify an image.
Moving onto HDRI
HDRI has been introduced in attempts to eliminate all previous problems. A HDRI not only produces reflection data but also includes emission and direction of light. A HDRI is usually a 360 degree view of an environment which is recorded by a series of photos that are stitched together; this can be done in camera or by taking a series of photos that are inline on the X axis.
JPEG 8 bit
You can achieve the same 360 degree picture in a JPEG folder. This is good as it provides an environment for a model with colour and quality but has no way near as much information as an HDRI. This format can provide reflective information for a model but will not include lighting exposure information.
A HDRI image will have multiple exposures; this is done by ‘bracketing’; a setting that can be placed onto a camera to record a number of exposure values (EV stops). The reason for this is so the user has more control over light temperatures and light values.
A JPEG folder will change in contrast and not exposure.
Below is an example of the amount of detail a HDRI image and retain:
Notice the difference in light intensity from left to right; this amount of detail would not be shown if a JPEG image was acting as the environment.
Light exposure;- panoramic photo and HDRI probe
There are two ways to retrieve all this information needed for an HDRI image. A panoramic shot is a 360 degree photograph taken with multiple exposure settings. The good thing about this as it will provide the user with immense detail meaning all reflections will be clear.
Another way would be to photograph a HDRI probe which provides an almost 360 view from one shot. The problem with this is that you will reflect the camera which is taking the photo and will not provide you with a full 360 interpretation. This process will need photoshop to erase the unwanted reflection, although this process is quicker as you will only needs few shots at multiple exposures.