Blender Lighting Plug-in - Workflow

This workflow tutorial teaches how to use HDR Light Studio with Blender via the Connection.
Watch the HDR Light Studio - Quick Start video first to learn the key concepts of using HDR Light Studio.

Ensure you have installed both the HDR Light Studio main application and then the HDR Light Studio Connection for Blender.
For compatibility, ensure you are running 'at least' these HDR Light Studio and Blender versions...
•   For rendering with Cycles or Eevee: HDR Light Studio Xenon Drop 1 and Blender 2.83
•   For rendering with RenderMan: HDR Light Studio Xenon Drop 4 and Blender 2.83
•   For rendering with Octane: HDR Light Studio Xenon Drop 4.2 (2022.0426) and Blender Octane Edition 2021.1.5_26_3+ (Windows only) or 2022.1.BX2_27_1+ (Windows & Mac OS X)

If you'd prefer to learn with a video tutorial - you can watch our Blender: Getting Started video

STEP 1: Start Blender and load your Blender project

Before we start to use HDR Light Studio to light this scene.... let's make sure the scene is ready to light first.
 
Camera View
Make sure you have a camera setup with the final composition for the shot that you want to light. If you move the camera during the lighting process, the reflections of the lights will move and this will ruin your lighting.

Existing Lights
Ideally, your scene should not contain any lighting before using HDR Light Studio. You may have set up some environment lighting during the look development for the scene, so now is a good time to delete or hide this lighting. If you have an LED light that's part of a product for example, then this is a part of your scene and should be kept. We simply want to avoid confusion by mixing lights created with HDR Light Studio and those not created with HDR Light Studio. A blank lighting canvas is the best place to start.

Tip: If you have an HDRI map you want to edit that's already lighting the scene, hide or delete this light and load the HDRI map into HDR Light Studio once it's open.

In this example, we are using Cycles (see Figure 1).

STEP 2: Go to the HDR Light Studio Connection Add-on panel

Go to 'World Properties' and expand the 'HDR Light Studio' section (see Figure 2).
Not seeing HDR Light Studio Connection? See our installation instructions

STEP 3: Start HDR Light Studio from Blender

On the HDR Light Studio connection panel, click the Start button (see Figure 3)

Important: The HDR Light Studio API used to talk with Blender uses TCP/IP. When first starting HDR Light Studio you may be asked for permission for it to use TCP/IP. It will require ports 5555,5556,5557 and 5558 to be open. Please allow these TCP/IP communications for the Add-on to function correctly.

The connection add-on creates a new world called HDRLS World, even if there is already a non HDRLS World set up.

RenderMan Users: Instead of creating a new world, the connection add-on creates a new RenderMan/Pixar Dome Light called HDRLS Dome Light, and it will be visible in the Blender Outliner. This is the case even if there is already a non HDRLS Dome Light set up. Once the HDRLS Dome Light is set up in the project, HDR Light Studio will always use that Dome Light to connect to. A shader network is created for the HDRLS Dome Light where the environment texture always references an up-to-date temporary HDRI map file which can be replaced and updated by HDR Light Studio

Once the HDRLS World is set up in the project, HDR Light Studio will always use that World to connect to. A shader network is created for the HDRLS World where the environment texture uses an Image data-block called HDRLS World Tex that always references an up-to-date temporary HDRI map file which can be replaced and updated by HDR Light Studio (see Figure 4).
 
You can read more about the HDRLS World here.

The HDR Light Studio interface should look like the interface shown in Figure 5. If it doesn't, go to Window > Layout > Load > Default > Blender.

If you are using a single display, watch the Getting Started video on this page to see how to customize the HDR Light Studio interface, so you can see Blender and HDR Light Studio at the same time.

The current HDRI map design in HDR Light Studio is shared with Blender as a temp proxy (lo-res) image. A proxy is used because it's faster to calculate and faster for Blender to load during the iterative lighting design process. When the lighting design changes in HDR Light Studio, this image is updated in Blender to use a new temp with a new file name, to ensure the renderer uses the new image even when caching images.

STEP 4: Import your Blender Scene into HDR Light Studio

In this demo we are using 2 displays, with HDR Light Studio on one display and Blender on the other (see Figure 6).
Press the play button on Render View [HDR Light Studio] (see Figure 7).

The Import Scene Geometry panel will pop up.
 

STEP 5: Choose your import options

Let's use the default settings. Press Import (see Figure 8)

Using this play button the current frame will be exported, and if a subdivision surface modifier is applied to meshes, this will be applied to the exported model too. The model is exported into HDR Light Studio as a temporary Alembic file. You can send your 3D model into HDR Light Studio by using the Export section in the HDR Light Studio panel in Blender. This provides more control over what is exported.

HDR Light Studio will only support perspective projection cameras.

We will use the Render View in HDR Light Studio as the interface for positioning lights on the model. It will give us real time feedback (see Figure 9).

STEP 6: Let's create our first light in HDR Light Studio

By default, LightPaint is set to Reflection mode in this view. This means lights are positioned to reflect in the chosen location on the 3D model when using LightPaint (see Figure 10).
Learn about LightPaint here.

Drag and drop a Preset Light onto the 3D model in the Render View (see Figure 11)

The Preset Light has been added to the lighting design in a location that is reflecting where the light was dropped on the 3D model.

You will see:
•   A new light in the Light List in HDR Light Studio (see Figure 12).
•   The new light has been added on the Canvas (HDRI Map View) in HDR Light Studio (see Figure 12).
•   The Render View has been updated to show the lighting effect on the loaded 3D model (see Figure 12).

 

STEP 7: Reposition a light using LightPaint

You can see that the LightPaint tool is active in the toolbar within the Render View [HDR Light Studio] (see Figure 13).

Click and Drag on the 3D model to reposition the selected light from the Light List.
This is a very interactive way to light your shot, placing lights directly on the 3D model where you want them (see Figure 13).

 

STEP 8: Start interactive rendering in Blender

Start interactive rendering by clicking on the 'Viewport Shading: Rendered' icon in the top right of the viewport, to see what the lighting looks like in your renderer (see Figure 14).

Cycles and Eevee Users: You can switch between Cycles and Eevee at any time. Our lighting is compatible with both.

We can leave Blender rendering as we work in HDR Light Studio. When lighting changes in HDR Light Studio, it will update Blender to use the new lighting. If the scene is large and the render inside Blender is updating slowly, you can produce test renders from time to time instead of leaving Blender's Live Render Preview running. It is up to the user to judge this performance and decide what to do.

STEP 9: Choosing Area Light Type - Cycles & Eevee only

Cycles and Eevee users have the option to choose between 2 different methods of area light creation:
1. Mesh Emitters
2. Blender Area Lights
 
The type of area light that should be used for the project depends on the user's workflow and preference. Read the comparison between Mesh Emitter and Blender Area Lights to find out more about which type is more suitable for your needs.

Return to Blender's interface and, in the HDR Light Studio connection panel, choose your preferred Area light type.
In this example, we are using Mesh Emitters (see Figure 15).

If you are using Octane or RenderMan, you will not see this setting and you may skip to Step 10.

Area Light Type is a global setting and will determine the type of all area lights made by HDR Light Studio in the scene. It is also dynamic, meaning that the setting can be tweaked at any time to convert all area lights made by HDR Light Studio from Mesh Emitters to Blender Area Lights and vice versa.  

STEP 10: Creating Area Lights

So far the light we created is on the HDRI map. With a single setting, this light can be removed from the HDRI map, and created as an Area light in 3D space in Blender.

Return to HDR Light Studio, and enable the Area Light check box in the Light Properties panel for the selected light that we have created in Step 6 (see Figure 16).

As a result of enabling the Area Light setting, these things instantly happen:
•   1. The Light in the Light List gets the suffix [AreaLight] and the text is now yellow - clearly showing which lights are Area Lights (see Figure 17).
•   2. The light is removed from the HDRI map lighting the Render Views (but is still represented and shown on the Canvas) (see Figure 17).
•   3. Additional Area Light properties have been added to the Light Properties for this light, with a default Smart Dolly distance of 1,000 units  (see Figure 17).
•   4. An Area light has been created in the Render View [HDR Light Studio], mapped with the HDR texture to control its appearance (see Figure 17).
•   5. An Area Light has been created in Blender for the selected renderer - mapped with the HDR texture from HDR Light Studio, and matching the size and position of the area light in HDR Light Studio  (see Figure 17).

To find out more about the behavior of area lights created by HDR Light Studio for your renderer, read Area Lights in Detail.

 

STEP 10: Adjust the distance of the Area Light from the 3D model

Reduce the Smart Dolly slider value to move the light closer to the 3D model (see Figure 18).

HDR Light Studio has a scene scale setting that is useful when working with area lights in Blender. If the area lights are too close or too far away by default when using the slider, adjust the Smart Dolly Scalar value in Preferences. This value scales all area lights made with HDR Light Studio. You can watch a video to learn about this scale setting here.

On the Blender user interface we can see:
 
•   1. The Area Light geometry in the viewport (see Figure 19) (If not, the area light is most likely too far away from your scene. To learn more about Smart Dolly - click here)
•   2. Area lights made with HDR Light Studio are shown in the Outliner inside HDR Light Studio Lights (see Figure 19)
•   3. Shaders set up for the created area lights - mapped with HDR content (see Figure 19)

Please Note: Area Lights created by HDR Light Studio in Blender will not be named to match those in HDR Light Studio. You can see the HDR Light Studio light name by going to the Object Properties for the light in Blender, and looking at the Custom Property called strName. This is not important as there is really no need to adjust the lights created by HDR Light Studio in Blender.

STEP 11: Moving Area Lights

In HDR Light Studio, use LightPaint in the Render View [HDR Light Studio] to move the Area Lights, just like moving a light on the HDRI map (see Figure 20).
In fact area lights are controlled just like any other light in HDR Light Studio, with the addition of the distance settings (Smart Dolly and Dolly Multiplier).

STEP 12: Area Light Spread - Cycles only

Important: For compatibility ensure you using 'area light type: Blender Area Light' and are running 'at least' Blender 2.93 and HDR Light Studio Xenon Drop 4.

You can use the spread setting to change the light emitting from the area light.

This is how the spread setting changes the light emitting from the area light.

 
Here you can see the effect of changing this setting, see how the light becomes more focused on the scene with lower settings.

 

STEP 13: Finalizing the lighting design

Once you are happy with your lighting, press the Render Production HDRI button in HDR Light Studio (see Figure 21).
It says HDR on it.

Set your Production Render settings and Press Render in this panel. Notice how the 'Orientation' is already set to 'Blender/Blender', this ensures that the rendered HDRI map is mapped correctly in the host, i.e. Blender (see Figure 22). For more information see: Production Render Dialog

The production quality content will be calculated and saved as files on disk. The connection will automatically update Blender to use these final high-res area lights and HDRI map images.

If any further changes are now made to the lighting in HDR Light Studio, all content will be updated to use the updated proxy versions again.
So please ensure you 'Stop' the HDR Light Studio connection after you have produced your production lighting by Pressing the Stop button (see Figure 23).

If you stop the HDR Light Studio connection and have not produced a production render of the final lighting, the temporary lo-res files will be replaced with blue HDR Light Studio logo images. This serves 2 purposes: It stops the Blender scene from referencing the temporary HDR files that will disappear, causing missing file errors in the future, and it makes it clear to the user that the lighting has not been produced at a high quality avoiding the low quality temporary files being used by accident.

 

STEP 14: Save the Blender scene to store the HDR Light Studio lighting project

If you would like the HDR Light Studio project to be saved in your Blender scene for next time you load this Blender scene, you should save your Blender scene now. This way the scene state matches the HDRI map and area lights that are currently in the HDR Light Studio project.

Saving and loading HDR Light Studio projects
HDR Light Studio projects can be saved from the HDR Light Studio interface at any time during the lighting process as a HDi file (native HDR Light Studio project file), even when using HDR Light Studio via a connection. If you were to open HDR Light Studio in a connection with Blender, this project can be loaded into HDR Light Studio using Project > Open Project. The lighting design would load into HDR Light Studio replacing its current design, and would then be synced back into Blender. This is how you can move lighting between Blender projects or between other supported 3D software.

STEP 15: Switching to a different Renderer

If you decide to now light the same scene using a different renderer, we recommend that you Purge Lights (see Figure 24) before switching to a different renderer and starting HDR Light Studio again - find out more about the Purge Lights function here.

Purging Lights can also 'fix' issues related to issues with synchronization and accuracy updates between HDR Light Studio and Blender - find out more here.