Author Topic: Camera import: y-axis greatly skewed  (Read 935 times)

Offline yesmine

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Camera import: y-axis greatly skewed
« on: December 26, 2014, 04:07:51 AM »
I have an FBX Camera file (exported from a simple Terragen 3 animation I believe), that I have imported into a Maya scene to test for matching movements in Maya. It is a very simple movement, a slow 90-degree rotation on the x-axis with a very slight rise in y-axis altitude, as if watching a vehicle go by and then standing up as it passes. What is confusing is that the y-axis rise seems greatly stretched, more like rising 30 feet rather than 2 feet. It is hard to say whether the x-axis rotation is also distorted, but the foreground dropping completely out of sight makes it obvious the y-axis is far off what it should be. Checking the graph editor does show a large rise in the graph of y-axis, which should be a fairly slight rise.

Matchmoving the TG scene to get the camera movement is a possibility, eventually, but it would be a time saver if an exported camera FBX could be made to work correctly. Is this a known issue, or does anyone have an idea why y-axis movement would be so distorted?
Thank you,

Offline Oshyan

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Re: Camera import: y-axis greatly skewed
« Reply #1 on: December 30, 2014, 04:00:01 AM »
I'm not sure what the issue is but I do know there are various conversions and whatnot that need to happen correctly, as well as potential unit variations which may be coming into play. As far as I'm aware there is no known issue with this kind of data interchange with Maya, and we do have users who are doing similar sorts of things. But unfortunately I don't know enough about it to really troubleshoot much further, nor do I have a copy of Maya to test with. Matt is currently having some family time for the holidays, but hopefully he'll have a chance to look at this soon. I'll bring it to his attention, I think he'll be able to take it a bit further than I.

- Oshyan

Offline Matt

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Re: Camera import: y-axis greatly skewed
« Reply #2 on: January 06, 2015, 03:34:42 PM »
Can you get an exact readout of the values on the last frame, and compare between the two programs?

Terragen's units are always considered to be metres. When you export an FBX from Terragen, the FBX contains the information that the units are metres. When another program, e.g. Maya, imports the FBX, often the FBX importer will automatically convert between units. If Maya's units are centimetres, 1 unit in Terragen should convert to 100 units in Maya. But it sounds like your import is off by a different factor. Maybe your units are set to feet? Also, if I recall correctly, the Maya FBX importer also has some additional scaling options that you need to look at carefully.

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