Since Thea Darkroom renders only the current frame, you have to use Picture Viewer in order to render multiple frames in the same scene. Picture viewer always employs Thea Render's production engine set in Render Settings.
Once you start the rendering procedure, the first thing that happens is the transferring of the scene into the engine. For any subsequent frame, the scene will be checked and only the modified objects will be retransferred. Of course, the same procedure applies when the scene is rendered in Interactive mode. If you change the current frame, the rendering will stop, the scene will be checked and all modified objects will be retransferred.

Thea Object Tag
To change the way the objects operate during transferring procedure works, you have to use Thea Object Tag. For now, it has only two commands, but it will be extended to include more transferring options affecting other aspects of the workflow.

Trasnferring Type
This option is used to alter the way an object operates during transferring.

  • On Tweak: This is the default transferring option in all objects (even those that don't have a Thea Object Tag applied to it). In this option, after the very first scene transferring, the object will be retransferred only if it is modified, otherwise it will be ignored and it will remain in the engine in its current state.
  • On Frame Change: With this option the object behaves exactly as in On Tweak, but also it is forced to be retransferred every time the timeline frame is changed.
  • Never Retransfer: Other than the very first transferring, the object will not be retransferred even if it has been modified.

Transfer Buttun
Forces the object to be retransferred immediately. If Never Retransfer is selected in Transferring Type, the transfer command will be ignored.

Motion Blur
Motion blur is supported on either geometry (primitives, polygons, mographs, particles, render instances) or camera objects. In order to produce this effect in the final rendered image, a motion spline has to be calculated by Thea engine. To do that, Thea For Cinema 4D has to transfer future and past PSR (Position, Scaling, Rotation) matrices for each animated object. To generate these matrices and transfer them in the engine, a motion tag is required to be added on the movable object. This tag is inherited by the hierarchy children (same as material texture tag).

Enables/Disables motion blur for the specific object.

Motion Accuracy
Since the motion spline consists of keyframes, they have to be retrieved from each animated object and transferred into the engine. This parameter defines the way the keyframes will be retrieved.

  • Use Keyframes: During the PSR matrix retrieval, only the object's keyframes will be used.
  • Use Timeline Frames: There are objects that even though they are movable, they don't have any keyframes assigned to them (e.g. particle generated objects). Using this option, Cinema4D's timeline will be used to generated the past and future PSR matrices that the engine requires to calculate the motion blur. This is the most generic method to retrieve the matrices since it doesn’t require the object to have actual keyframes in the timeline.
    Frame range (+/-)
    This option defines the length of the motion spline that will be passed in the engine. For example, if the current frame is 35, the motion blur will be calculated for frames 30 - 40.

Total timeline frames used
This option defines the number of frames that will be used to create the motion spline. The higher the value, the more accurate is the motion blur. Always, the minimum frame, the maximum and the current one will be added in the motion spline regardless the value of this parameter.


Use Keyframes: Consider an animated object that has keyframes in positions 3, 9, 14, 20. So, in the end [b]only[b] 4 matrices will be transferred in the engine for this particular object, retrieved by these 4 frames. This will be fast, but not very accurate for complex animations.
Use Timeline Frames: Let's say the current frame is at 15, the frame range is +/- 10. The motion spline will have a length of 21 frames (5 to 25). With 50% as "Total timeline frames used", only the half of these 21 frames will be used to produce the matrices that will be transferred in the engine. So, the matrices in frames 5,7,9,11,13,15,17,19,21,23,25 will create a motion spline.

Important notes

  1. Motion blur is depended on Camera's shutter speed. So, to affect freely the blurry trail of the animated objects, a Camera object with a Thea Camera Tag is required. At this point, the tag's shutter speed can be used to make motion blur more tense.
  2. The option Use Timeline Frames can be used, even if the object is animated based on keyframes. That way you can increase the frame number in motion splines, resulting in a more accurate motion blur effect.
  3. What matters in the motion blur calculation, is the position of the object in each future/past frame, regardless the method that causes the animation (keyframes or emitters).


  1. Motion Blur on deformable meshes is not currently supported. It will be added on a later TheaForCinema4D version.
  2. Xpression and Constraint tags might cause issues in object's position during the calculation of motion blur. As a workaround, use “Dynamics” or “Generators” in tag's priority.
  3. If the animation comes from particle emitters, they have to be baked.