Precision or mathematic problem

Precision or mathematic problem

Hi,I'm working on a rendering software (http://spectralbattle.wordpress.com/) and use several SDK to test my code. Using several SDK allow me to check if the errors are in my code... or in the SDK.When I use the Intel SDK I have some problems :Here is a rendering with AMD SDK :https://picasaweb.google.com/polarlights01/CornellAMD#5592014900335257794Here is the same rendering with Intel SDK :https://picasaweb.google.com/polarlights01/CornellIntel#5592017101324392082The problem can be seen on the top of the box, a "normal" sounds to be inversed !The normal orientation is simply computed with a dot product like this :int isInside = (dot(Ng, I) < 0);N = isInside ? -Ng : Ng;I have also try to compute directly the dot product (Ng.x*I.x+Ng.y*I.y+Ng.z*I.z) , but I have the same effect !Maybe the error is somewhere, but what I see is that I don't have this problem with AMD SDK !

http://spectralbattle.wordpress.com/
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Finally,I have found a way to fix it !But really it is not related to my code ! I have just replace some operation with corresponding float3 operations and it works !So, there is a bug somewhere :-PThanks

http://spectralbattle.wordpress.com/

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