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CHOP's value limit?

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Alejandro Echeverry
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Hi!!

I have been working with CHOP's to normalize impact values; But now i have an odd problem, I have an impact that has 1.400.000 of impulse value, when I pass that info to my normalize tree in CHOP's all drop's to zero.

I have created a scene to test if CHOP's have a limit of values to manage with this tree to normalize a value(maybe is the math chop I don't know); If I put a value grater than 99999.996 chop's give all to zero.

What's wrong with my scene.

Thanks.

Attachments:
normalizeCHOPs.hipnc (62.5 KB)

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edward
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When I load the file in H11.1.94 (Win7 64-bit), I get the attached picture in the CHOP network. It looks correct?

Attachments:
normalizeChops.png (4.8 KB)

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Alejandro Echeverry
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Thanks Edward for the fast response!!!

are you change the default file's value to a greater number other than 99999.996?

If you do maybe is a build bug, I'm on 11.1.67 Ubuntu 10.10 x64.

I'll try the last build.

Thank you.
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Alejandro Echeverry
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I have update Houdini to 11.1.94 build and have no luck, still if I put a value greater than 99999.996 chop's drop to 0.

Also tested in Win 7 x64.
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Dennis Weil
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I tried your scene with Houdini 11.1.22 and I'm getting the same error. It seems like its some kind of precision loss due to single float values. As soon as the value goes above 99999,996 it gets rounded to 100000 which means the decimal is shifted to the right (sorry, but I don't know how to express myself in a better way). I can't explain why exactly this poses a problem (maybe someone can help here), but a I found a workaround. You have to “normalize” your values to another range first (like 0 to 1000) and then normalize these values again.

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edward
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alejandro
are you change the default file's value to a greater number other than 99999.996?

Where? Please upload your file modified so that it shows the problem.
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Alejandro Echeverry
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The attribute create node namely value_0 has a value of 99999.996, if you change that value to a greater number, the CHOP tree that i have created to normalize the input values drops to zero.

Here are the file.

Attachments:
normalizeCHOPs.hipnc (62.9 KB)

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edward
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Ah, I needed to change the value to 100001 before the problem shows up. It looks like there are some optimizations in the Math CHOP that fail due to precision here. I'd try manually doing this with a VOP SOP instead.

I'll fix the Math CHOP for H12.
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Alejandro Echeverry
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Thank you very much Edward!!!
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