I'm following the Blender Guru tutorial and I've done everything as described in the tutorial, but as I pressed E to add the dribbles for the icing two issues happened:
1) It seems way more sharp than it did for the guru
2) (Important) The dribbles are always inside the donut instead of on top
Seeing how you've enabled face snapping, the issue is with how you've extruded the edge. If you took a cross-section of the donut shown below, your icing is cutting into the donut, represented by the highlighted line. Since you've also got a very thin solidify modifier, the icing isn't thick enough to push outside of the donut.
Rather than just extruding once, consider splitting it into multiple segments, so it follows the surface of the donut more closely. Notice how parts of the icing wireframe end up going beneath the donut mesh, but its close enough so that the solidify modifier (which was hidden so you could see the wireframe) could push the icing above the donut's surface.
I ran into the same problem, but I've solved it and will share it with you. Modifier - Note the value of "Offset" in the "Solidify" option. The result is different in the negative direction and the positive direction. In the blender guru, it is set to positive. This option determines whether the surface will be thicker on the front or the back side. It is important to note that the snapping feature is not for the solidified look, but rather the surface is snapped.
It looks to me as if you are extruding the icing in the Z axis (up/down) only, so that it is going down into the donut. As I recall, he pulls the dribbles out sideways as well. to make them follow the surface of the donut.
Ok old thread but I think I figured something out:
The snapping of the icing to the donut's surface works just fine. The meshgrid vertices are perfectly aligned with the donut surface. However, if I check how they looked like before I applied the dragging to it, I can see that the vertices are actually a fair bit ABOVE the donut.
The clipping through the donut only appears after the icing vertices are snapped onto the surface of the donut.
The problem is the following: The thickness of your mesh extends from the surface downward. So if you snap your icing onto your donut, the thickness will always be below the donut's surface, because that's the starting point of the thickness. What you need is for the thickness to grow in the opposite direction, so a negative thickness:
Observe the gap between the icing and the donut before dragging:
This is the clipping at the same place in object mode
If you use a negative thickness for your icing, the thickness will grow upward instead of downward, so the icing will no longer dissapear into your donut because it extends from the donuts surface upwards:
