MtI 3.4

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ior
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Joined: Tue Aug 24, 2010 11:47 am

Re: MtI 3.4

Post by ior » Wed Jan 23, 2013 11:36 pm

MtI 3.4 changed the size of grid unit length. I had to raise 100 times the grid unit in order to achieve the same results.

I had also to put an exposure time 10000 times higher.

What is correct, as before, or as now?

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CTZn
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Joined: Thu Nov 16, 2006 4:34 pm
Location: Paris, France

Re: MtI 3.4

Post by CTZn » Thu Jan 24, 2013 12:45 am

Scene scale: on a new scene or an old scene ? Make sure that "only new" is unchecked in the Indigo Scene Definition tab of the Render Settings.

This option can lead to highly confusing situations: materials replacing others or missing, meshes replaced by some written for another scene, mesh not reflecting edits during render and last but not least, whatnot. A very dangerous option that skips mesh export if the output file name is referencing an actual .obj file on disk.

Eposure: beware of the indigoSpectrum blackbody's gain wich is at 0.01 by default. This is a very high value for an environment. Use the indigoSpectrum preset bb_backgroundBalance to set the gain in such a case. The attribute will show to be set at zero but it's not, the value is very small be not confused:

Code: Select all

getAttr indigoSpectrum1.gain
// Result: 1e-005
If you believe that the errors are different or persistent please provide more info or a Maya scene.

edit: there are several camera parameters that will affect the exposure. Pretty much all of the the ones relating with the film and optics.
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ior
Posts: 166
Joined: Tue Aug 24, 2010 11:47 am

Re: MtI 3.4

Post by ior » Thu Jan 24, 2013 4:12 pm

It is an old scene.
I do not use indigo spectrum, I used material emission with a base emission->100%white, as emission scale->lumens and as emission value->1.
In camera I got camera aperture->1, exposure time 0.1, filmISO->1200, EVadjust->10.
In grid unit length I got 0.01.
That was in MtI 3.2.12.0.

And now in MtI 3.4.17b I hat to change exposure time to 1000 and grid unit length to 1 to achieve the same results.

I can provide a scene If these are insufficient.


Iv got two maya versions with each MtI versions to test this, I had to install them manually to specific version folders, It would be good that when we source the script, it Installs MtI plugin and scripts to that maya version folder, instead of common folders.

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CTZn
Posts: 7240
Joined: Thu Nov 16, 2006 4:34 pm
Location: Paris, France

Re: MtI 3.4

Post by CTZn » Thu Jan 24, 2013 6:13 pm

I recommend that you drop mti 3.2.12 completly, stick with the latest release working for you as a rule of thumb.

The camera values that you are reporting are aberrant because the environment value is extremely weak.

Sticking with the default tonemapping and the default camera settings, you must find the right emission value in the first place.

You can use a white at 100% but then either set the V as in HSV to something very high with the default emission scale, or set a more powerfull emission scale.

Camera and film come out tuned by default, you do the lighting. Using a simple sun & sky is also good for some calibration.

You can leave the emission to black, to mti this means "discard the attribute" because a black emission would make no sense at all.

I'll update the installer at some point to let the user choose between the current maya install or all of them.
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