I’m trying to add 3D objects to some drone footage of a house for blender practice. Now I should say that I don’t know much about cameras, and this may not be a blender specific question, so please forgive my lack of knowledge.
In order to solve the camera, I’m in the “Motion Tracking” screen layout trying to figure out how to use all the tools in order to get the best track possible for my scene. I figure matching the settings in the tabs for “Camera” and “Lens” to the original camera are very important for an accurate track, but I really have no idea how to do this. How do you find the camera settings somebody used if all you have is the video? is there meta-data i can access that will tell me? Is there a safe standard setting for these options?
Also, I know the shot was taken with a GoPro Hero4 Black, but know none of the settings used. There does not seem to be a preset for this camera in the preset tab either.
It can be done but it is more complicated than just setting up the camera. Reason behind that is the gopro has a fisheye lens to it which distorts edges and that is what gives most tracking softwares a hard time. I do believe though that gopro has a software to remove that distortion from your footage and would make life a lot simpler. Then you can add back in the fisheye distortion afterwards if needed. But here is a quick run through of a track done with gopro footage. https://www.youtube.com/watch?v=zREPFFLPMjQ
Thanks for the reply. Something I noticed while reading the Blender manual for motion tracking was this part,
“All cameras record distorted video. Nothing can be done about this because of the manner in which optical lenses work. For accurate camera motion, the exact value of the focal length and the “strength” of distortion are needed.”
I’ll try following along with the video you linked me, though it is hard to notice any distortion in my video.
No problem, and it is correct that most all lenses have some sort of distortion to them. Another way to also adjust for it to figure out the distortion is to use a grid displayed so you can adjust the camera settings till the grid lines are straight. Once I find the video about doing this I can link it cause it explains a little better than I can typing it out.
I did some research on the GoPro Camera settings, and found this: https://havecamerawilltravel.com/gopro/gopro-fov-linear/
The article says newer GoPros (Hero 5 and 6) have fisheye compensation using the FOV setting of “Linear”. There was a firmware update for the Hero4 which enables this mode. This leads me to believe the linear FOV was used in this shot, which explains why there seems to be no distortion at the edges.
This means I wouldn’t have to compensate for distortion inside Blender, and that i would only need to know the sensor dimentions, which can be found here: http://vfxcamdb.com/gopro-hero4-black/ and the focal length.
Actually, would focal length even be important since there is no distortion?
Glad to hear you got it all straightened out. And to get a good solve quality that has little to no slipping as much info that you can input into the tracking scene the better quality track you will get out of doing so. But again, glad that you got it all solved now “no pun intended”
