![]() ![]() If you know your lens distortion k1 and k2 coefficients, insert them into the "Distortion coefficients" field: Google Cardboard SDKs approximate the ideal distortion model by exposing and coefficients. Where is the distorted image point, is the undistorted image point, is the distortion center (principal point), and is the distortion coefficient. This type of radial distortion can be corrected using Brown's distortion model: The typical lenses used for mobile VR headsets exhibit pincushion distortion: Google Cardboard SDKs for Unity and Android can automatically correct for the radial lens distortion. Note: If this is the case, re-measure the tray to lens-center distance on your physical viewer, and make sure that you have chosen a correct "Screen vertical alignment" option.Incorrect tray to lens-center distance: When viewing in your VR headset, the lens center markers appear not centered vertically.(Verify this by viewing the scene with both eyes, and then closing one eye at a time). Correct tray to lens center distance: when viewed in your VR headset, the red lens center marker appears vertically centered. ![]() Here are a couple of criteria that can help you to determine whether the tray to lens center distance is entered correctly: To ensure that you have entered the screen vertical distance correctly, verify that the red markers appear in the vertical center of the visible field-of-view, when viewed through your VR headset. If you chose "BOTTOM" or "TOP" options for "Screen vertical alignment", measure the tray to lens-center distance from the bottom/top of your viewer planes respectively and enter it into the "Tray to lens-center distance (mm)" field. CENTER: Choose this option if the center of the smartphone screen is always vertically aligned with the center of the lenses in your viewer.TOP: Choose this option if the smartphone is aligned with the top plane of your viewer when fully inserted, or if the viewer attaches to the top of the phone.This option applies for most viewers, including the original Google Cardboard. BOTTOM: Choose this option if a smartphone is always aligned with the bottom plane of your viewer when fully inserted, or if the viewer attaches to the bottom of the phone.Here are more detailed explanations for different screen vertical alignment options: If this is the case, re-measure the inter-lens distance on your physical viewer and readjust the values in the "Inter-lens distance" field.Ĭhoose whether the smartphone screen is aligned to the bottom or to the top of your viewer when the smartphone is inserted, or whether the smartphone is always vertically centered with respect to lenses.In extreme cases, you might be seeing two separate lens separate markers instead of one. Incorrect inter-lens distance: When viewing in your VR headset, the lens center markers might appear blurry or duplicated.The inter-lens distance should be equal to the distance between the lens center markers when measured with a ruler or a caliper.Your eyes are able to converge on the lens center markers in a relaxed state, and you do not feel eye strain when converging on the markers. Correct inter-lens distance: When viewed in your VR headset, the red lens center markers appear sharp and clear.Here are a couple of criteria that can help you to determine whether the inter-lens distance is entered correctly: If your viewer comes with an adjustable inter-lens distance to accommodate varying IPDs, measure the average distance between the screen and the lenses.Īfter measuring and entering the inter-lens distance into the viewer profile form, ensure that your eyes can clearly converge on red lens center markers in the scene. Measure the distance between the centers of your viewer's lenses using a ruler or a caliper, and enter this distance in millimeters into the "Inter-lens distance (mm)" field. ![]()
0 Comments
Leave a Reply. |