Multiple Gradients on a mask

Question

I want to use a gradient mask with multiple gradients.

Layer 1 (bottom) will have an image of a skyline.

Layer 2 (above) will have a solid colour, with the layer set to multiply.

I don't want to use that effect on the buildings in the skyline, so I will use a layer mask with a gradient to make the bottom half of the image the normal colour, with the gradient fading in the multiplied layer. Thus the clouds/sky will have the multiplied colour on them.

On one side of the image is a tall building, so I want to do a second gradient on the same mask which will be diagonal and in addition to the first gradient. This will ensure the tall building is not effected by the multiplied layer as the first gradient would finish shorter than the building.

I then want to repeat that gradient on the other side, but effectively the opposite (flipped), so the diagonal will go the other way, how would I achieve this?

Answer 1

Use a group or smart objects....

Two masks altering a single layer by using a group for the second mask.

or apply the mask to the layer, then "Covert to Smart Object" and apply a mask to the Smart Object.

Note that you can add masks and "Convert to Smart Object" several times, essentially allowing you to apply multiple masks to one layer repeatedly (Creating a type of rabbit hole to the original layer data).