3D RGBD Camera & C4D Import

On 27/09/2017 at 02:59, xxxxxxxx wrote:

User Information:
Cinema 4D Version:   r18/19 
Platform:   Windows  ; Mac  ;  Mac OSX  ; 
Language(s) :     C++  ;  XPRESSO  ;


Paul Melvin at Maxon recommended I get in touch with regards to some API, SDK and C++ work for an exiting new project of mine that is underway and one that is set to be very experimental in terms of 3D scanning and positional tracking.

The project is a music video for Avalon Emerson, an emerging female techno producer that is gaining publicity quickly all around the world.

We're shooting elements of the project at Kew Gardens in London with Stereolabs' RGBD "Zed" camera. We'll use the data gathered from it to match-move our 4K camera and extract 3D elements of the scenery for compositing. The cool thing about the Zed is that it uses stereo odometry and depth sensing to generate textured meshes which can be used for all kinds of applications from robotics, drones, 3D printing and most excitingly for me, VFX!

> > Right now I'm facing a few complications that will require help using C++ with the Zed's SDK. The main problem I'm facing is the Zed's internal coordinate system. I need to export Zed's quaternion XYZ positional/rotational data to Cinema 4D's HPB system and struggling to get my head around it all. I'm not a C++ developer, but Stereolabs have assured me it is a simple task. With the shoot date set for the 7th and 8th of October, and the hand-in for the 17th, I'd love to have the workflow ready.

> >
For the Zed's SVO files, I'll ideally need a built exporter to extract the camera's positional data and textured OBJ mesh ready to open in C4D without the need for any additional calibrations to the rotational order and PSR. I'm thinking the ultimate format would be FBX as I believe it can hold camera and mesh data and is readable in other 3D apps. There would need to be some attention to frame-rate too as the recommended recording settings for the ZED are 60fps at HD720.

There are no sample SVO files available for download as far as I know but my teammate has shot some material with the Zed which he may be able to forward over to you when he gets a moment.

Here's an overview of the coordinates system:

> Zed Positional Tracking

Here are the more in-depth links for Zed's SDK and API:
SDK Download

> Zed Documentation

> Zed API Referance

> Zed Classes, Structs, Unions and Interfaces

For now, I've attached some already-extracted elements from the Zed's SVO recording format.

We've been looking for solutions all over and haven't managed to find anything particularly user friendly yet so It would be great if you could let me know your thoughts with regards to this all!

Kind regards,

Hayden Martin

On 28/09/2017 at 02:28, xxxxxxxx wrote:

Hi Martin, first of all welcome to our Cinema 4D development-related community.

With regard to your support request, although your request looks complete in terms of provided documentation, we , as the SDK Team, can't develop plugins for our customers. That said, usually our developers community has proved to be supportive on this kind of requests usually getting privately in touch with member asking for developing a plugin.

So far, I encourage you to have a look at our Matrix and Quaternion classes reference and to the Matrix Manual where the topic you're looking for is properly covered. On top of this, looking at the data provided, I actually see no quaternion-formatted data in the .CSV but simply XYZ-rot and XYZ-pos values which should be easily loaded in Cinema 4D.
To me a simple script, parsing your .csv line-by-line and setting the camera movement at specified frame, could easily make your day. Finally, what still puzzle me is the TimeStamp (in nanoseconds) which actually never change from the beginning to the end of the file.

Best, Riccardo

On 28/09/2017 at 04:15, xxxxxxxx wrote:

Here a sample for doing what you want to achieve in python.
There is small issue regarding coordinate and orientation since it's appear to not be the one describe here http://www.stereolabs.com/documentation/overview/positional-tracking/coordinate-frames.html

So maybe a picture with the actual world axis and the mesh + the track of the camera would be nice.

Moreover I'm not sure, I still need to investigate but I guess my script suffer of a memory leak in AddKey function. Then use it with care.

#Import csv stereolabs inside c4d
# https://plugincafe.maxon.net/topic/659/13815_3d-rgbd-camera--c4d-import
# graphos 28.09.2017
#   Copy - past in Script manager
#   Select a camera
#   Run
#   Select csv file
#   Enjoy ! :)
import c4d
import csv
class Data(object) :
    timestamp = None
    rot_x = None
    rot_y = None
    rot_z = None
    pos_x = None
    pos_y = None
    pos_z = None
    def __init__(self, data) :
        if not isinstance(data, str) : return
        # Build a list from string
        datas = data.replace(" ", "").split(";")
        buffer = list()
        for i, value in enumerate(datas) :
                x = None
                if not i:
                    x = int(value)
                    x = float(value)
        # Check list is correct
        if len(buffer) != 7: return
        # Assign value
        self.timestamp = buffer[0]
        self.rot_x = buffer[1]
        self.rot_y = buffer[2]
        self.rot_z = buffer[3]
        self.pos_x = buffer[4]
        self.pos_y = buffer[5]
        self.pos_z = buffer[6]
    def __str__(self) :
        return "time: {0}, rot_x: {1}, rot_y: {2}, rot_z: {3}, pos_x: {4}, pos_y: {5}, pos_z: {6}".format(
    def _getChildrenWorld(self, obj) :
        buffer = list()
        children = obj.GetChildren()
        for child in children:
        return buffer
    def _setChildrenWorld(self, obj, list_matrice) :
        children = obj.GetChildren()
        if len(children) != len(list_matrice) : return False
        for i, matrice in enumerate(list_matrice) :
            doc.AddUndo(c4d.UNDOTYPE_CHANGE, children[i])
        return True
    def setWorldPosition(self, obj) :
        m = obj.GetMg()
        m.off = c4d.Vector(-self.pos_x, self.pos_y, self.pos_z)
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, obj)
    def setWorldRotation(self, obj) :
        old_pos = self._getChildrenWorld(obj)
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, obj)
        rot = c4d.Vector(-self.rot_x, self.rot_y, self.rot_z)
        m = c4d.utils.HPBToMatrix(rot)
        m.off = obj.GetMg().off
        self._setChildrenWorld(obj, old_pos)
def checkValidCSV(filepath) :
    if filepath[-3:] != "csv": return False
    file = open(filepath, "rb")
        line = file.readline()[:-2]
        str_to_check = "Timestamp(ns);Rotation_X(rad);Rotation_Y(rad);Rotation_Z(rad);Position_X(m);Position_Y(m);Position_Z(m);"
    if line != str_to_check: return False
    return True
def getTrack(obj, trackID, channelID) :
    # Find the Track
    param = c4d.DescID(c4d.DescLevel(trackID, c4d.DTYPE_VECTOR, 0),
                       c4d.DescLevel(channelID, c4d.DTYPE_REAL, 0)
    track = obj.FindCTrack(param)
    # Create if no track found
    if not track:
        track = c4d.CTrack(obj, param)
        doc.AddUndo(c4d.UNDOTYPE_NEW, track)
    return track
def addKey(obj, track, frame, value) :
    # init var
    time = c4d.BaseTime(frame, doc.GetFps())
    curve = track.GetCurve()
    # Find the key
    key = curve.FindKey(time)
    found = False
    # If there is no key create one
    if not key:
        # init our key
        key = c4d.CKey()
        track.FillKey(doc, obj, key)
        # Set value for our key
        key.SetTime(curve, time)
        key.SetValue(curve, value)
        # Insert our key
        doc.AddUndo(c4d.UNDOTYPE_NEW, key)
    # If we found an already existant at current time, jsut set the the value.
        key = key["key"]
        # Set new key value
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, key)
        key.SetValue(curve, value)
def main() :
    # Get selected camera
    obj = doc.GetActiveObject()
    if not obj or not obj.CheckType(c4d.Ocamera) : return
    # Open file and check validity
    filepath = c4d.storage.LoadDialog(c4d.FILESELECTTYPE_ANYTHING, "Select csv data")
    if not filepath: return
    if not checkValidCSV(filepath) : return
    # Read data and store it in list(datas)
    datas = list()
    with open(filepath, "rb") as file:
        reader = csv.reader(file)
        for row in reader:
    # Create Keyframe for each data
    # I acutally limit to the first 600 frame since there is memory leak and we can already so rotation are not good
    for i, data in enumerate(datas[:600]) :
        # Set Frame
        doc.SetTime(c4d.BaseTime(i, doc.GetFps()))
        # Get tracks
        posTrackX = getTrack(obj, c4d.ID_BASEOBJECT_POSITION, c4d.VECTOR_X)
        posTrackY = getTrack(obj, c4d.ID_BASEOBJECT_POSITION, c4d.VECTOR_Y)
        posTrackZ = getTrack(obj, c4d.ID_BASEOBJECT_POSITION, c4d.VECTOR_Z)
        rotTrackX = getTrack(obj, c4d.ID_BASEOBJECT_ROTATION, c4d.VECTOR_X)
        rotTrackY = getTrack(obj, c4d.ID_BASEOBJECT_ROTATION, c4d.VECTOR_Y)
        rotTrackZ = getTrack(obj, c4d.ID_BASEOBJECT_ROTATION, c4d.VECTOR_Z)
        # Get world data
        current_frame_world_pos = data.setWorldPosition(obj)
        current_frame_world_rot = data.setWorldRotation(obj)
        # Get relative data
        current_frame_local_pos = obj.GetRelPos()
        current_frame_local_rot = obj.GetRelRot()
        # Add Key for current value
        current_frame = doc.GetTime().GetFrame(doc.GetFps())
        addKey(obj, posTrackX, current_frame, current_frame_local_pos.x)
        addKey(obj, posTrackY, current_frame, current_frame_local_pos.y)
        addKey(obj, posTrackZ, current_frame, current_frame_local_pos.z)
        addKey(obj, rotTrackX, current_frame, current_frame_local_rot.x)
        addKey(obj, rotTrackY, current_frame, current_frame_local_rot.y)
        addKey(obj, rotTrackZ, current_frame, current_frame_local_rot.z)
if __name__ == '__main__':

Moreover looking a bit the source you probably use this http://github.com/stereolabs/zed-examples/blob/master/positional tracking/src/main.cpp for create the csv file. Which say

initParameters.coordinate_system = COORDINATE_SYSTEM_RIGHT_HANDED_Y_UP;

But I didn't succes to convert it to good thing inside c4d.
Importing your obj with Flip X Axis enable or Swap X and Z axes give the same result and looking to your video it's seem to be the good orientation, but my matrix mathematics are sadly not good so maybe someone can help.

About timestamp as Riccardo pointed this out, I simply make one line = one frame.