AR Marker Camera Matrix Transform Problem.

[pwsnow]

Dear Forum,

Has anyone had any experience with the ARToolKit plug in with Vizard? I have a question I need to ask about the camera matrix transform. We are currently using the trial version to ensure we can sort this problem out before purchasing the full version.

We have a scenario in which we want to track markers on cubes on a table that can be moved. Currently we have 2 cameras, but we will be using 3 in total. The user sits at the table and the two cameras are located just in front of the user to the left (facing the user’s left side) and just in front of the user above pointing down (facing the table). The setup works find and all the markers can be picked up by the cameras. However the reported eulers of the markers are incorrect.

I have experimented by breaking it down to one camera (the second one, looking down facing the table) and playing around with the camera matrix transform (as per the Vizard 4.0 Documentation on ARToolKit) using the <camera>.setMatrix(matrix) function. But with no luck. The eulers being reported are incorrect.

I understand that the marker positions are relative to the camera matrix transform. Just trying to work it out.

For example when I have the camera looking directly down at the marker I should get an euler of [0,0,0] reported from the marker. After applying a 90 degree pitch rotation vector to a matrix and applying that to the camera matrix I get [-1.48,-4.76,-47.86] which is nearly there bar the roll value.

Thanks for any help,

Peter