HOW CAN I recreate the light Distribution from real lights?
This is a great question. If you turn on a light or go onto Google and search ‘Lights’ then you’ll see that internal lights have specific and bespoke light distributions. The way that the light falls off and distributes out from the bulb is unique to each bulb. This effect isn’t something that can be recreated using a standard light but can instead be created using something called an IES file. These files contain the exact distribution of light for a specific lamp. Thankfully most lighting manufacturers will provide these files free of charge from their websites. To find out what the light distribution of a file is you can use a nice free viewer called ‘Iesviewer,’ which can be downloaded from their site at www.photometricviewer.com.
Once you’ve got the IES file that you need we can begin to load it into our 3D software. For the purposes of application we’re going to focus in on V-ray but you can apply these principles to any 3D software which allows it. Firstly, head over to the Create panel and to Lights followed by Vray. Select Vray IES and drag the light in the viewport to create it. Then head over to the properties panel and scroll down to the VRAYIES Parameters rollout. The specific parameter you need is entitled ‘ies’ and it has a button next to it which by default will say None. We need to insert into this parameter the IES file that we previously downloaded. Click on the button and it will bring up a dialogue box. Navigate to where your IES file is stored and double click on it. That will then be loaded into your light. Do a quick test render and see what the result is.
If you want to further customise the light then in the properties section you can also adjust things like the power of the light and its colour. You shouldn’t have to change many (if any) of the properties because IES lights should work pretty well out of the box. The only properties I generally change are the power of the light and its colour.