Author Topic: Reversed values in imported chan file  (Read 816 times)

Offline sboerner

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    • Steve Boerner Typography & Design
Reversed values in imported chan file
« on: May 06, 2016, 06:22:57 PM »
I've been playing around with importing chan files created in Maya (with a mel script). Most things seem to be working.

The exported values are correct when when I check the chan file in a text editor. But when it's brought into Terragen via Camera > Import > Import File the Z position, and Y and Z rotation values are all multiplied by -1. So in the curves editor they are the inverse of what they should be.

Funny thing is, everything works just fine when I split the chan file into two files one for translation (first three columns) and one for rotation (columns four through six) and import them separately with the Position and Rotation animation buttons.

I've searched the forums and it sounds like others have had similar issues, but I couldn't find a reference to this one in particular. Is this normal behavior?

Also tried importing fbx, but that's giving me strange rotation values.



Offline sboerner

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    • Steve Boerner Typography & Design
Re: Reversed values in imported chan file
« Reply #3 on: May 06, 2016, 07:54:52 PM »
Thanks much for those links. I had seen the first but didn't recognize the description of this issue in Matt's pseudocode - it's there all right. The second link confirms it. Good to know about the rotate order. I was really wondering about that.

I can split the file or do the conversions in Excel. I'll see which one's simpler; may depend on how many frames there are.

Just tried importing a Maya .mov file, by the way, but kept getting an "FBX: Unable to initialise import file" fatal error. Strange.

Thanks again.

SB


Offline sboerner

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Re: Reversed values in imported chan file
« Reply #4 on: May 07, 2016, 03:19:22 PM »
For the record, I was able to get everything to work but it took an extra twist. It may be this specific file or I'm missing a step on export/import, but here's what worked for me. The motion path exported from Maya is a circular orbit around a target. It was exported with the camera's rotate order set to ZXY per Matt's recommendation. The exported .chan file was opened in Excel and linked to a new table with the following relationships:

Translate:
X' = X
Y' = Y
Z' = Z

Rotate:
X' = X
Y' = (Y + 180)
Z' = Z

So for example these lines from the original table:

234   -364.934   150   -6.91641   -10   -91.0867   0   53.131
235   -364.99    150   -2.72002   -10   -90.4275   0   53.131
236   -364.997   150    1.48592   -10   -89.7664   0   53.131
237   -364.955   150    5.70098   -10   -89.1042   0   53.131


Become:

234   -364.934   150    6.91641   -10   -88.9133   0   53.131
235   -364.99    150    2.72002   -10   -89.5725   0   53.131
236   -364.997   150   -1.48592   -10   -90.2336   0   53.131
237   -364.955   150   -5.70098   -10   -90.8958   0   53.131


And when pulled into Terragen via Camera > Import > Import File these are converted to:

234   -364.934   150    -6.91641   -10   88.9133   0   53.131
235   -364.99    150    -2.72002   -10   89.5725   0   53.131
236   -364.997   150     1.48592   -10   90.2336   0   53.131
237   -364.955   150     5.70098   -10   90.8958   0   53.131


Can't vouch for rotate Z since this file doesn't use it, but based on Matt's post those values also would be negated again by Terragen.

Filing this away to (someday) test with more complex paths . . .

SB

 

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