【有奖问答】SDK中volumeRender示例数据的类型改变后错误

float u = (x / (float) imageW)*2.0f-1.0f;
float v = (y / (float) imageH)*2.0f-1.0f;
其中u,v的作用是什么?
我将uchar类型的数据改为int型数据后出错。

WARNING: Exception in file ‘d:\bld_sdk10.pl\devtools\sdk10\compute_3.0\sdk10\com
pute\c\common\src\stopwatch.cpp’ in line 57
Detailed description: No StopWatch with the requested name exist.
c:\documents and settings\administrator\桌面\c++ primer\volumerender\volumerende
r.cpp(332) : CUTIL CUDA error.
WARNING: Exception in file ‘d:\bld_sdk10.pl\devtools\sdk10\compute_3.0\sdk10\com
pute\c\common\src\stopwatch.cpp’ in line 57
Detailed description: No StopWatch with the requested name exist.
c:\documents and settings\administrator\桌面\c++ primer\volumerender\volumerende
r.cpp(332) : CUTIL CUDA error.
请按任意键继续. . .