invisible textures...

Questions about Anatomist manipulation

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colabiel
Posts: 11
Joined: Mon Jan 31, 2005 4:22 pm

invisible textures...

Post by colabiel »

Hi to all,
I have a problem while loading some particular textures.
If the values of the texture I load is included in [-1e-9 ; 1e-9], there is no problem.
But, If the values of the texture I load is included in [1e-9 ; 1e-6], the texture is invisible, even if I play with the palette...
The values seems to be rounded if they are verry of the same sign ?

Thanks
Nicolas
Nicolas Lefebvre
trainee in MEG/EEG center
LENA UPR 640 CNRS
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riviere
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Post by riviere »

Hi,
Well, I see what happens. Texture values are used to address coordinates in the palette image (this is done directly by OpenGL). These coordinates must be in the range [0-1] so if the texture values are outside this range, they are rescaled to fit into this normalized interval. But if they already fit into it (which is true in your case), they are keps unchanged. However the palette image must cover the full range of possible values [0-1] in a given (limited) number of pixels. With very small values like 1e-6, all values fall into the same palette pixel.
I will change this rescaling criterion to also rescale the internal texture data if the actual range is small.
Denis
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riviere
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Post by riviere »

OK it's fixed, it will be in the next update (I don't know when).
Denis
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