IMPORTANT NOTE:

The source .c4d files should ideally be re-saved from a most recent and up to date copy of Maxon's CINEMA 4D program via the "File / Save Project for Cineware..." (R21 or newer) or the "File / Save Project for Melange..." (R20 or older) menu command. Considerably older versions of CINEMA 4D requires that the "Save Polygon Objects for Mélange Exchange" checkbox be enabled via its Edit / Preferences dialog box. CINEMA 4D .c4d files with only mesh geometry in them should load okay but any other files with procedural geometry or deformed objects will not load any data unless first re-saved as per this Cineware/Melange explanation.

Important Runtime Information and Caveats of the Okino C4D File Importer

This import converter reads in files encoded in the Maxon CINEMA 4D (.c4d) file format.

Runtime Caveats:

1. This importer requires a "geometry cache" to be associated with each imported non-mesh object. This is guaranteed to exist when you have re-saved the CINEMA 4D scene using the "File / Save Project for Cineware..." (R21 or newer) or the "File / Save Project for Melange..." (R20 or older) menu command. If you wish to see what a specific object within CINEMA 4D will look like after being imported into Okino software via its geometry cache, right click on that object's name within CINEMA 4D and choose Make Editable. This will essentially convert the object into its mesh geometry cache variant.

   Note: HyperNURBS objects (meshes sub-divided using a Catmull-Clark sub-division operator) have two mesh density states within CINEMA 4D: Sub-divisions for the editor and Sub-divisions for the renderer. The caches saved to disk will use the Sub-divisions for the editor. Hence, the mesh density you see after loading the file into CINEMA 4D will be the mesh density you get when importing into Okino software.

2. If "Array Objects" created in CINEMA 4D R15 (or newer) do not look correct after import then you can resolve such an issue through one of two actions:
   
   
   • Disable the option called "Save Animation for Melange" in the CINEMA 4D "Preferences / File" menu (for older versions of CINEMA 4D).
     
     
   • Or, as an explicit modelling operation, you can right click on any "Array Object" nodes within CINEMA 4D and use the "Make Editable" option. That will collapse the complex array object into a form which will be properly exported into the "Cineware/Melange Geometry Caches".
   
   
3. HyperNURBS on top of skinned, animated meshes: these will have to be rebuilt inside of CINEMA 4D before being imported into Okino software. Let's take the following example which shows a base polygon mesh being deformed by a skinning modifier and then sub-divided by a final HyperNURBS modifier:

   

   This setup cannot be supported because the HyperNURBS (mesh subdivision) is done after the mesh deformation by the skeleton joints (the skinning modifier). This is exactly the same situation as with 3ds Max and Maya.

   To correct this situation, go into CINEMA 4D and right click on the HyperNURBS object then choose 'Current State To Object'. Now re-apply any animation and skinning to this new and final sub-divided mesh model. Delete the other nodes which are no longer used.

4. Procedural animation must be 'baked' into explicit keyframe animation data. Refer to the section How to Bake Animation Curves in CINEMA 4D.
   
   
5. If a procedurally generated object imports with none of its animation data then right click on the object's name inside of CINEMA 4D and choose 'Make Editable'. For example, if a cube object is used within an Array Modifier then this importer must use the special "geometry cache" to import the final arrayed objects, but animation data may not be associated with this "geometry cache".
   
   
6. For unsupported UVW texture projection methods of CINEMA 4D you can aid this importer by changing the non-UVW-Mapping projection types into explicit UVW mappings within CINEMA 4D yourself:
   
   
   1. Choose a "Texture Tag"
   2. Go to the Tags menu of the Object manager panel.
   3. Choose Generate UVW Coordinates
   4. Repeat for each Texture Tag which does not explicitly use a UVW Mapping.
   
   
7. CINEMA 4D allows for multiple bind poses for skinned meshes (the bind poses are stored in the weight tags and each mesh object can have several weight tags applied). These multiple bind poses is not supported outside of CINEMA 4D. Only the first bind pose is imported.
   
   
8. Stop tags - try not to use them. Using "Stop tags" within CINEMA 4D will prevent an object and its children from having a geometry cache. This importer requires this geometry cache to import the object properly, otherwise no object will be imported (unless it is originally a mesh object).
   
   
9. Splines: CINEMA 4D supports a wide variety of 3D spline types. Many are imported in a 1:1 manner as linear, B-Spline or Bezier curves into Okino software. For non-supported parametric curves they will be imported as "linearized curves" into Okino software via the geometry cache created by CINEMA 4D - if you do not want your splines converted to linear then right click on the curves within CINEMA 4D and choose Make Editable, after which you should choose Bezier as the new curve type.
   
   
10. CINEMA 4D Array objects will be imported using the following hierarchy:
    Array Node -> Array Null Node -> Render Instance of Child Node -> Render Instance of Child Node -> Render Instance of Child Node -> Etc... -> Children of Array Null Node
    
    
    
11. CINEMA 4D Symmetry objects remove animation from the object that is doing the symmetry operation. If animation on symmetry objects is critical then you should use a CINEMA 4D Array object with one copy of an object to simulate the Symmetry object.
    
    
12. CINEMA 4D Instances and Render Instances are loaded as true Okino "instances of master geometry instances". In other words, only one geometry object is defined, then 1 or more virtual instances of it are placed into the scene. If you wish to import each instance as its own explicit copy of geometry then go into CINEMA 4D and right click over each object to do Make Editable. This will turn each chosen instance into its own geometry object (along with its own geometry cache). If you disable Render Instance on a CINEMA 4D panel then an explicit geometry copy will be made internally, including its own geometry cache, otherwise enabling this checkbox will cause the instance to point to the geometry item directly and not create any local cached geometry copy.
    
    
13. CINEMA 4D Render Instances will instantiate ALL geometry in their target objects. This includes all of its target children that were used to make a cache. The following structure explains this:
    - Instance of HyperNurbs - HyperNurbs -> HyperNurbs Cache -> Cube (Forced hidden) Then instance of HyperNurbs's structure will look like - Instance of HyperNurbs -> Instance of HyperNurbs Cache -> Instance of Cube (Forced hidden)
    
    
    
14. CINEMA 4D will search for texture maps within the tex sub-directory folder. In Okino software you will either have to ensure all texture maps use absolute path references, or you will have to add an explicit path to the tex directory to the Okino texture file paths search dialog box.