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Do you want to improve the lighting in your CGI?

Learning how to improve the lighting in your CGI is not rocket science, but there are techniques that we use. By understanding a few key lighting concepts I want to illuminate you and show you how to better your CGI, but before we do; let’s talk about why the sky is blue…

Let there be light.

Under intense and unimaginable pressure, hydrogen atoms are forced together in a huge release of electromagnetic energy, of which visible light makes up a small portion of this energy.

This is the beginning of the journey of a single photon from the centre of the burning ball of gas that we call our sun until it reaches our eyes.

Improve the Lighting in your CGI - The sun
Light is formed as a by-product of nuclear fusion

After its tumultuous birth, our photon then takes, on average, 6 minutes to leave the surface of the sun and fly across the vast, 150 million kilometers of hard vacuum until it reaches our atmosphere.

Improve the Lighting in your CGI - Golden hour at sea
Light then scatters through the atmosphere, turning the sky blue during the day and redder at dawn and dusk.

As our photon passes through the big air bubble that surrounds the earth, it bounces off and passes through nitrogen atoms which make up nearly 80% of our atmosphere.

Our photon is a package that contains all of the colours of the rainbow – it just so happens that light on the bluer end of this spectrum scatters through nitrogen most effectively… which is why the sky is blue.

Improve the Lighting in your CGI - an exterior CGI of a garden office made by Ventham Construction

On a physiological level, we have evolved not only to love light but to need it.

Light is the key component that enables us to see, gives us security, and stabilises our circadian rhythms which helps us to sleep deeper and more restoratively.

It improves our moods, decreases depression, and even increases cognitive performance such as reaction time and activation.

On a fundamental level, we have an innate and primal relationship with light that can be traced all the way back to the roots of our shared evolutionary tree.

“I sense Light as the giver of all presences, and material as spent Light. What is made by Light casts a shadow, and the shadow belongs to Light.” Louis Kahn, American Institute of Architects Gold-medal winning Architect

Improve the Lighting in your CGI - Louis Kahn's National Assembly in Dhaka, Bangladesh
Louis Kahn’s National Assembly in Dhaka, Bangladesh

Lighting in CGI.

Modern render engines and most real-time game engines calculate lighting in a way that aims to emulate reality.

By definition, rays are traced (note: ray-tracing), from light sources as they then travel through 3D space and bounce off or scatter through surfaces.

Ray tracing software determines the number of times that a ray can bounce off or through a surface – the bigger the number of bounces, the harder the PC has to work, but generally the more realistic the result. 

Improve the Lighting in your CGI - An interior CGI of The Priory in Tetbury

As experienced and industry-leading producers of CGIs, we wholeheartedly recommend V-Ray as our ray-tracing program of choice.

We use this in conjunction with SketchUp and have done so for nearly a decade now.

Improve the Lighting in your CGI - An exterior CGI of Paragraph 79, Kea House, Devon

Feel free to take a look at what our CGI production team is getting up to using this software combo!

These lights have to come from somewhere though, right?

Whether it is the sun, a light bulb, or a candle; it is the job of the 3D artist to add these light sources to the 3D space and program them to emit light realistically.

Improve the Lighting in your CGI - A preview of a 3D scene, lit using a Dome Light. The HDRI image used is from PG-Skies.
A rendered preview from PG-Skies.com of a scene lit by a dusk HDRI.

Check out our article on how to use Dome Lights to create night-time CGIs.

As humans, we respond differently to different environs and lighting plays a big part of that. Anything that we see has a direct link to the subconscious, and this is what CGI artists tap into when working with lighting in a visualisation.

How do I put this into practice?

If you have read this far, you already understand the power of lighting within a CGI.

We need a structured workflow to better enable us to generate realistic and emotive lighting setups within our work…

If you are relatively new to CGI production, I recommend our Access into V-Ray for SketchUp course!

Day two of this three-day course is dedicated purely to lighting.

We explore what light sources that we have available to us, and how we go about adding these into a scene.

We then explore the concept of ‘Three-Point Lighting’, which gives us a fail-safe method of programming the lights within our scenes to work together in a photorealistic way.

Improve the lighting within your CGI - Scout Farm with lights toggled on and off

If you already have a good foundation, and simply want to improve the lighting in your CGI, look into our Top-Up courses – the premise is simple:

  1. You pick what you would like to learn
  2. A bespoke, coaching session will be designed by us and then pitched to you before you commit to anything
  3. Once you are completely happy with the custom learning material on offer, this is when we schedule a coaching session – we book these out in half-day blocks, to ensure that you have ample time for study and information retention.
  4. The session is held online and is screen recorded – which means you can watch it back when practicing on your own.
  5. Upon completion of the course, we extend a helping hand by offering an after-care period of 30-days, whereby as you take this knowledge into professional practice; you can come to us with any questions that you may have.

All of our courses, now taught online, aim to give you the tools to consistently advance your visualisation skills and improve the lighting in your CGI.

Archilime Academy online course provider 3d modelling visualisation cgi

Brought to you by the Archilime Academy.

 

 


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Dome lights: how do I use them to create a night time CGI?

You may not know it yet, but a dome light is the answer to creating ever-more realistic lighting setups within your CGIs…

Let’s break it down…

In a day-time scene, we have direct sunlight to illuminate our scenes. Direct light also scatters through the atmosphere and illuminates our environment.

A preview CGI from Peter Guthrie. Used to light a 3D scene using a HDRI within a dome light
HDRIs from PG-Skies.net. is a great way to illuminate your night scenes.

V-Ray considers both direct and indirect illumination as two separate light sources.

To create a night-time scene, we require a technique to remove direct sunlight, whilst being able to create a night-time environment.

To do this, we use something called a Dome Light

A flattened, spherical HDRI from Peter Guthrie. Used to light a 3D scene
A flattened, spherical HDRI from PG-Skies

A Dome light is a type of V-Ray light that surrounds our entire model, forcing light inwards. Images can be loaded into these light sources, which enables the user to simulate real-world environments by using panoramic HDR images. 

Learn more about the benefits of a Dome Light on our Access into V-Ray for SketchUp course

I like to think of a Dome Light as a giant snow globe – with our model in the centre. We can choose what the sky looks like by swapping in different panoramic images.

Now that we know what dome lights are; what does this mean for you?

How to insert Dome Lights into your 3D scenes within SketchUp

Select the highlighted tool to add a Dome light into your scene. Putting this into practice is straightforward. Pick out the Dome light tool from your V-Ray toolbar…

Loading a bitmap image into our Dome Light.
Click on the chequered box to import your HDRI…

Load in your HDRI…

Preview of a scene lit by Dome light using a spherical panoramic, HDRI image
Rotate to ensure that your shadows are pointing in the correct direction!

Hit render! Don’t forget to rotate your dome light to adjust the position of the sun

 

Over the years we have come across many different sources for dome lights…

We would like to recommend just two…

A preview of a 3D scene, lit using a Dome Light. The HDRI image used is from PG-Skies.
PG-Skies provide rendered previews so that you know what the sky will look like once rendered.

For variety, we highly recommend taking a look at Poliigon. Besides offering free assets; they operate a simple, subscription-type service where, depending on your package, you obtain different amounts of credits every month to spend on HDRIs, textures or models

If you are looking for top-quality HDRIs, look no further than Peter Guthrie’s shop – PG Skies. This in-depth collection of ultra high-quality HDRIs contains skies for all occasions. The handy preview renders show each of these in action, to make picking out your favourite that much easier!

 

Archilime Academy online course provider 3d modelling visualisation cgi

Brought to you by the Archilime Academy