Exporting Cinema 4D assets for Lens

Kraken does not support viewing Cinema 4D assets in Lens directly. To view Cinema 4D assets in Lens, you must convert Specular/Gloss workflows to Metal/Rough, import the Cinema 4D asset into Blender, reapply any textures or values to the appropriate PrincipledBSDF shader, and then re-export the asset from Blender as a glTF file.

Converting Specular/Gloss workflows to Metal/Rough workflows

If the model uses a Specular/Gloss workflow, you must convert the model to Metal/Rough by following these steps:

1. Leave any Emissive, Opacity, Refraction, and Normal maps as they are.
2. Convert the Glossiness map to a Roughness map. You can do this conversion in an application such as Photoshop by loading the Glossiness texture map, inverting the colors or values, and saving as a Roughness texture map.
   

   

3. Create the Metallic map. The process is different depending on whether the model has only dielectrics, only metals, or both dielectrics and metals:
   • If the model is purely dielectric, create a texture map with the same dimensions as the other textures within the texture set. Then, give this new Metallic map a value of pure black RGB(0,0,0) and save it as a PNG file.
   • If the model is purely metal, create a texture map with the same dimensions as the other textures within the texture set. Then, give this new Metallic map a value of pure white RGB(255, 255, 255) and save it as a PNG file.
   • If the model has both dielectrics and metals, you must separate the model to distinguish them and generate a Metallic map. The two most common ways to do this are:
     • If the model has enough separation between the dielectric and metal objects, you can assign a color value of pure black to the dielectrics or pure white to the metals. Then you can export the values as a texture map or maps, such as a Diffuse map. You can use this new texture map as the Metallic map.
       
       For example, the model below has enough object separation between the dielectrics and the metals:
       

       

       
       The resulting black and white model looks like this:
       

       

     • Sometimes the UV layout is organized in such a way that you can select the dielectrics and metals separately. For example, you might be able to open an OBJ file into Substance Painter, select by mesh, polygons, or UVS and fill dielectrics or metals as pure white or pure black.
       
       For example, this model is separated into pure white and pure black areas based on its UVs:
       

       

       
       You might be able to do this in Photoshop or similar applications by saving the model’s UV Cage, importing the UV Cage into the application, and creating a Metallic map based on the UV clusters, as in this example:
       

       

4. Convert the Diffuse map to Base Color:
   1. In Photoshop or a similar application, import the Diffuse and Specular maps.
   2. Put the Specular map above the Diffuse map in the layer hierarchy.
   3. Apply a mask to the Specular map and use the Metallic map as the mask texture.
5. Repeat the process for other texture sets in the model.

This diagram shows a pure black Metallic map. In this case, the Base Color and Diffuse maps stay the same:

This diagram shows a pure white Metallic map. In this case, the Specular color is transferred into the Base Color map:

Here’s a more realistic example:

Converting Cinema 4D assets into glTF files

If the model uses a Metal/Rough workflow, follow these steps to convert it to a glTF file that Lens can display:

1. In Cinema 4D, with the scene that you want to export open, click File > Export > FBX.
2. In Blender, click File > Import > FBX.
3. Navigate to the FBX file and click Import FBX.

4. With the model now in Blender, go to the Shading tab at the top of the screen.

5. On the Shading tab, select the object. The applied PrincipledBSDF shader appears in the shader editor.

6. As shown in Exporting Blender assets for Lens, reapply the texture maps to the to the PrinciplesBSDF shader, as shown in this picture:

7. When you are done reapplying all of the texture maps, save the scene.
8. Click File > Export > glTF 2.0.
9. Give the file a name and then click Export glTF 2.0.

Now you can import the model into Kraken and view it in Lens by following these steps:

1. Import the model:
   – To add the model file to an existing Kraken asset, select the asset, go to the Files tab of the Preview panel, and add the model.
   – To add the model file to a new asset, click the + New button and import the model.
2. Select the asset, and under its thumbnail image click View this model in 3D.

For more information about Lens, see Lens Real-Time 3D Viewer.