HDR Light Studio is a standalone lighting application providing a set of tools and content dedicated to lighting 3D scenes. Using HDR Light Studio connected to Cinema 4D provides the ability to create custom HDRI maps to light your scenes, with lights chosen and positioned to provide the perfect effect on your model. As you work with HDR Light Studio, the lighting is updated in real-time in Cinema 4D, where you can see the lighting interact with your 3D scene. You can also create and control Area Lights using HDR Light Studio.
This workflow tutorial will teach you how to use the connection between Cinema 4D and HDR Light Studio.
It will not teach you how to use HDR Light Studio itself. Please see our 'Getting Started' content here to learn the HDR Light Studio interface and the basic features.
1. Start Cinema 4D and load the Cinema 4D project you want to light.
2. Open the HDRLightStudioC4D Connection plugin panel
Go to the menu: Plugins > HDRLightStudio4CD Connection (see Figure 1)
Figure 1: Opening the HDRLightStudioC4D Plugin panel
The HDRLightStudioC4D panel opens (see Figure 2).
Figure 2: HDRLightStudioC4D Connection plugin panel
Drag the panel and dock it into the C4D interface (see Figure 3).
Figure 3: Docked HDRLightStudioC4D Connection plugin panel
3. Use the 'Renderer' drop down in the Connection panel to select the Renderer being used for this project.
In this example we are using Corona Render (see Figure 4).
Figure 4: Choosing renderer
4. Press the 'Add Prebuilt Hook' button (see Figure 5).
This will create a new lighting environment setup for your chosen renderer that's set up so the HDR Light Studio connection will see and can control the environment image.
Figure 5: Adding a prebuilt hook
In Figure 6 we can see the HDRLightStudio.Corona node has been created and contains the environment setup for Corona Render.
This is now listed as the selected Environment Hook by the HDR Light Studio Connection.
Figure 6: HDRLightStudio.Corona node
5. Make sure you are looking through the Camera you want to light in the Cinema 4D interface, with that viewport active.
We are now ready to start using HDR Light Studio
6. Press 'Start' to start HDR Light Studio connected with Cinema 4D (see Figure 7)
Figure 7: Starting HDR Light Studio connection
The HDR Light Studio application will open and is now connected to Cinema 4D.
The HDR Light Studio connection has taken control of the image on the environment (see Figure 8).
Figure 8: File path points to a HDR Light Studio temp proxy image
The current HDRI map design in HDR Light Studio is shared with Cinema 4D as a temp proxy (lo-res) image. A proxy is used because it's faster to calculate and faster for Cinema 4D to load during the iterative lighting design process. When the lighting design changes in HDR Light Studio, this image is updated in Cinema 4D to use a new temp with a new filename, to ensure the renderer uses the new image even when caching images.
Using our latest version of HDR Light Studio and the Cinema 4D connection - the HDR Light Studio interface will now show 2 Render Views. On the left is Render View [Cinema 4D|Corona] (see Figure 9)
Currently this view is not compatible with Cinema 4D and Corona and can be closed! (Only using Cinema 4D R20 with Arnold, Octane, Redshift and Thea currently supports this Render View)
Figure 9: HDR Light Studio on startup with Cinema4D and Corona
We recommend changing the layout using the top menu: Window > Layout > Load > Default > Standalone
The HDR Light Studio interface will then contain the features you need to use HDR Light Studio with Cinema 4D and Corona (see Figure 10).
Figure 10: HDR Light Studio Standalone interface layout
Using 2 displays provides the best work flow, with HDR Light Studio on one display, and Cinema 4D on the other (see Figure 11).
Figure 11: Cinema 4D (left) and HDR Light Studio (right) running on 2 displays
6. Press the play button on Render View [HDR Light Studio] (see Figure 12).
Figure 12: Starting HDR Light Studio Render View
The Import Scene Geometry panel will pop up
7. Press Import (see Figure 13)
Figure 13: Importing the scene from Cinema4D to HDR Light Studio render view
By default the whole Cinema 4D scene is exported as a temporary alembic file and loaded into the Render View [HDR Light Studio].
To export only selected geometry into HDR Light Studio - see here
We will use this Render View in HDR Light Studio as the interface for positioning lights on the model, with real time feedback (see Figure 14).
Figure 14: HDR Light Studio render view with imported scene from Cinema 4D
Let's make our first light in HDR Light Studio ...
By default, LightPaint is set to Reflection in this view. So lights are positioned to reflect in the chosen location on the 3D model when using LightPaint (see Figure 15).
Learn about LightPaint here.
Figure 15: LightPaint mode set to Reflection
8. Drag and drop a Preset Light onto the 3D model in the Render View (see Figure 16).
Figure 16: Placing a preset light onto the model
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 17).
•You can see the new light added on the Canvas (HDRI Map View) in HDR Light Studio (see Figure 17).
•The Render View has been updated to show the lighting effect on the loaded 3D model (see Figure 17).
Figure 17: HDR Light Studio interface after creating a light
You can see that the LightPaint tool is active in the toolbar within the Render View [HDR Light Studio] (see Figure 18).
9. Click 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 18).
Figure 18: Using LightPaint to paint light on the model
10. Let's start Corona interactive rendering in Cinema 4D to see what the lighting looks like (see Figure 19).
Figure 19: Starting Corona interactive rendering in Cinema 4D
Corona starts interactive rendering using the lighting from HDR Light Studio (see Figure 20).
Figure 20: Corona Frame Buffer inside Cinema 4D (left) running with HDR Light Studio (right)
We can leave Corona rendering as we work in HDR Light Studio. When lighting changes in HDR Light Studio, it will update Cinema 4D > Corona to use the new lighting.
If the scene is large and rendering in Corona is updating slowly, you can produce test renders from time to time instead of leaving Corona interactive rendering running. It is up to the user to judge this performance and decide what to do.
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 Cinema 4D, mapped with the HDR content from HDR Light Studio.
11. Enable the Area Light check box in the Light Properties panel for the selected light (see Figure 21).
Figure 21: Converting a light into an area light
As a result of enabling the Area Light setting, these things instantly happen:
•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 22).
•The light is removed from the HDRI map lighting the Render Views (but is still represented and shown on the Canvas) (see Figure 22).
•A 3D Area Light mapped with the HDR light content (RGBA) is created in HDR Light Studio with a Smart Dolly distance of 1,000 (see Figure 22).
•A 3D plane with emitter shader is created in Cinema 4D, mapped with the HDR light content (RGBA), this can be seen lighting the shot in Render View [HDR Light Studio] (see Figure 22).
Figure 22: Light convered into an area light
12. Reduce the Smart Dolly slider value to move the light closer to the 3D model (see Figure 23).
Figure 23: Moving the area light closer to the model (LightPaint position)
HDR Light Studio has a scene scale setting that is useful when working with Area Lights in Cinema 4D. If the area lights are too close or too far away by default. Adjust the Smart Dolly Scalar value in Preferences. This value scales all area lights in HDR Light Studio.
On the Cinema 4D user interface, we can see:
•The Area Light geometry in the viewport (see Figure 24) (If not, the area light is most likely too far away from your scene. To learn more about Smart Dolly - click here)
•Area lights made with HDR Light Studio shown under the HDRLightStudio.Corona environment (see Figure 24)
•Shaders setup for the created area lights - mapped with HDR (RGBA) content (see Figure 24)
Figure 24: Cinema 4D interface after creating an area light
13. 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 25).
In fact area lights are controlled just like any other light in HDR Light Studio, with the addition of distance settings.
Figure 25: Using LightPaint to position the area light
When using the HDR Light Studio area lights, please note:
Renaming/deleting/duplicating these area lights in Cinema 4D (or any part of their associated shader network/file nodes) will cause problems!
14. Production Render
Once you are happy with your lighting, press the 'Production Render' button in HDR Light Studio (see Figure 26).
Figure 26: Production Render buttons
Set your Production Render settings and Press Render in this panel. Notice how the 'Orientation' is already set to 'Cinema 4D/Corona', this ensures that the rendered HDRI map is mapped correctly in the host, i.e. Cinema 4D (see Figure 27). For more information see: Production Render Dialog
Figure 27: Production Render Panel
The production quality content will be calculated and saved. The connection will automatically update Cinema 4D to use these final area light 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 28).
Figure 28: Stopping the HDR Light Studio connection
15. Save Cinema 4D scene.
If you would like the HDR Light Studio project to be saved in your Cinema 4D scene, you should save your Cinema 4D scene now. This way the scene state matches the HDRI map and area lights that are currently in the project.
16. 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 Cinema 4D, 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 Cinema 4D. This is how you can move lighting between Cinema 4D projects or between other supported 3D software.