How to create a slope in exisitng surface

I want the a slope so that liquid can flow from point A to point B with a gradual slope along the two paths shown with yellow arrows, any ideas. the existing half drain was made by substracting a pipe from the exisitng polysurface.

Thanks in advance !!!

I would undo the subtract, give the pipe the slope you need and then subtract.

Tried to extract the iso curves, three of them one in the center, and used cage edit command to tweak the centre one but results are not exact.

Thanks Nathan but the point is only the depth should have a slope the width should remain the same. So we dont disturb the exisitng geometry and just replace the drain

I’m guessing you want to keep the bottom curve as consistent throughout as possible, just higher walls where necessary.

Assuming you still have the initial curve you used to create the pipe I’d:

  1. ensure you get a closed curve - you can always add the sphere bit later
  2. use Pipe command with the radius you want
  3. run ChangeDegree, keeping the U to 3, but changing the V to 5 or 7 (I tested with 7). Important is that the number is odd, so you get a layer of control points right along the middle. ChangeDegree is also why we wanted to start with a closed curve - I found ChangeDegree doesn’t work with a non-closed curve.
  4. Use POn for the pipe surface
    5 Now you can tweak the bottom half of the control points on the surface

After that you can use the object in BooleanDifference as the cutter. Of course you should adjust for the spherical extra bit that you want in the lowest part.

Would this work for you?