iris_raj

12-11-2006, 12:47 AM

Dear GPU Programmers,

We are facing a problem of texture lookup problem.

We have a 1Dimensional texture of size 100 and as we know texture coordinates vary from 0.0 to 1.0. But as per chapter 24 of GPU Gems a texture coordinate can vary from 1 / (2*100) to 1 - 1 / (2*100) //Reference GPU Gems2 Page number387, 388. The calculation formula is ((1 - 1 / n) / n) where n is the size of texture. and

the interpolation type is LINEAR using GPU

When we try to look for texture coordinate having 10th value, the returned value differs from the actual 10th value. But if GPU interpolation is set as “POINT” then the correct value is returned.

As per the book GPU Gems2 the texture coordinate calculation is changed and the resulting formula is given above. Kindly notify us if any material regarding the above said issue is available. Also notify us if you have any concerns regarding the above assumptions or calculations.

RAJESH.R

NEST,TVM

We are facing a problem of texture lookup problem.

We have a 1Dimensional texture of size 100 and as we know texture coordinates vary from 0.0 to 1.0. But as per chapter 24 of GPU Gems a texture coordinate can vary from 1 / (2*100) to 1 - 1 / (2*100) //Reference GPU Gems2 Page number387, 388. The calculation formula is ((1 - 1 / n) / n) where n is the size of texture. and

the interpolation type is LINEAR using GPU

When we try to look for texture coordinate having 10th value, the returned value differs from the actual 10th value. But if GPU interpolation is set as “POINT” then the correct value is returned.

As per the book GPU Gems2 the texture coordinate calculation is changed and the resulting formula is given above. Kindly notify us if any material regarding the above said issue is available. Also notify us if you have any concerns regarding the above assumptions or calculations.

RAJESH.R

NEST,TVM