[Tutorial] How to use IES Textures in Blender
Using IES textures to enhance your lighting is one of the keys to achieve much more exciting and realistic results in your architectural renderings. Using them is really simple, though still lots of people do not know about their existence. In this short tutorial, I’m going to show you where you can find lots of FREE IES textures, and how to use them in your projects to make your visualizations look better!
To show you the difference between regular lights and those with IES, I’ve prepared two renders – one without IES, where I use the regular Bledner spotlights, and the other one with using IES Textures:
Remember, that this technique works ONLY in Cycles
Best free IES texture packs
First of all, you’ll need to get the IES textures. Throughout the Internet, you can find lots of great free IES packs. Below I’ll list some of the packs that I’m using in my projects:
- LeoMoon IES Light Pack – the package of free 32 IES textures
- Renderman by Pixar IES Profiles – amazing package of great (and free) IES textures from Pixar itself
How to add IES textures in Blender
That’s actually pretty simple, but may be tricky! First of all, add the lamp, that will be using the IES Texture. The best approach is to add simple point lamp or a spotlight, if you want to limit the lamp’s spread angle. What’s also very important is the distance between the lamp and the wall. Your lamp should be located as close to the wall as possible, to get the sharper lobe effect, but I’ll talk about that later.
When ready, go to lamp settings. Press Use Nodes button. Then go to the shader editor, the same that you’re using to create your materials.
You should see the default nodes setup
Then press SHIFT+A and select Texture -> IES Texture
Connect the IES Texture node to the Fac input and switch the source to External
Now is the tricky part! Open the file browser with the folder icon and go to the directory with your IES textures. You should see duplicated files – the image file and the one with the same name, but .ies ending, without the preview. Select the .ies file, so the one with NO preview, otherwise it won’t work. Many users intuitively select the file with the preview, usually .jpg or .png, but this one is not the IES profile and will not affect the lighting effect.
In my example, I’ll be using Thee_Lobe_Umbrella from RenderMan IES pack.
If you set the correct texture, add some cube next to your light and change the viewport display to rendered to see the effect. If everything is set properly, you should see the lighting lobe on the ‘wall’.
The work is not done yet, as the light still may need some more tweaks to look better. Usually, the settings that need to be changed are color, strenght and lamp size.
Color – Light Temperature
First of all, you should set up it’s color, and I recommend to use the light temperature to do that.
To use temperature, you need to add one more node in you shader editor. This node is called Blackbody. Press SHIFT+A and find Converter -> Blackbody. Connect this node to the color input of your Emission node.
Simply 4000K is the neutral temperature. Everything above is cold light (more bluish), everything under is warm light (more reddish). For standard lights, I recommend using values around 2800K – 3500K for the best results. The value of 6500K will be the white color. Play with this node yourself and check out the changes in the rendered view.
Many IES textures causes the strong overexposure. This is why strength of the lamp needs to be adjusted. You can do that either in the nodes editor in the IES Texture node strength or in the lamp settings, and I recommend the second option, as it gives better control, and is more approachable. Unfortunately the power values are usually false, and 10W for one IES can be something completely different, than 10W for the other one. You must tweak it and find the best result yourself.
When you first add your IES, you may be confused why the lobe is so smooth, when it should be much sharper. This is caused by the large size of the default Blender lamp (0.25m). Tweak this value to something around 3-5cm (usually referencing to the real world lamp size is the good practice). Try to avoid extremely small values like 0-1cm, usually the lamps with the lobe effects are never that small, and remember that smaller lamp size may cause the bigger noise in your renders.
Distance from the wall
The last very important condition is what I’ve mentioned in the beginning – lamp’s distance from the wall. Basically, the closer lamp is to the wall, the sharper will be lobe’s effect. I will demonstrate it on the lamp with the size of 1cm, to demonstrate it better.
This is what’s happening when the lamp is almost touching the wall (putting the lamp exactly on the wall is not recommended, as it may be killing the light itself). Now see what happens if you move the lamp away from the wall:
The effect is “bigger” but much more smoother than the initial one. You’ll always need to find the best result yourself, it’s always depending on what you want to acheive.
Lamp’s rotation and scale
What is also very important with IES profiles is that they are “directional” effects. That behave like you’d been using the real reflector, so they are affected by rotating the lamp. I’ll rotate the lamp (in Blender viewport of course) so it’ll be more pointing at the wall
This operation may be a little bit confusing when you’re using the point lamps, as you won’t be able to see the direction they are heading. In this case, I just recommend switching the lamp’s type into Spot, then you’ll be able to see the lamps direction.
Unfortunately, the default setting causes that the lobe effect is limited by lamp’s size, by default it’s 45 degrees. So in the lamp settings just increase the size into the desired value – 180 degrees would be the best.
How to scale IES Texture in Blender
All right, so let’s now play with the size of our IES effect. Try to scale your lamp in the viewport. As you see, nothing happens, except the lamp’s viewport size. But there is an easy way to scale the effect of the IES texture.
Go back to the Shader Editor. You’ll need to add two nodes to your settings – Mapping and Texture Coordinate. If you are using Node Wrangler built-in addon (I really recommend to turn it on!), simply select the IES Texture node, and press CTRL+T. Otherwise, just add the two nodes with SHIFT+A
When ready, connect the nodes as shown below. It’s important to select Normal as the Texture Coordinate – when you’ll add the nodes with the Node Wrangler, you will need to change the connection from Generated into Normal
Now our setup is ready. Now, play with the Scale Z value and to decrease the lobe’s radius, you will need to decrease this particular value. You can also tweak the other scale values here to get the effect you want – like always it’s just up to you and your needs.
I hope you can now easily add IES Textures to your projects in Blender, making the lights looking astonishing. You’ll probably discover yourself, how useful is this technique for improving your scene’s lighting and making your renders look better and more realistic.