Wave effect does not render maxima and Y Offset is very coarse.

[sslupsky]

Describe the bug
When rendering the wave effect on an icicle the result is not scaled so that the full vertical scale is used.

The way the Y Offset is being generated renders as a very coarse adjustment. Using the 1-8-1 icicle pattern the offset does not visually change the render until about 13.

To Reproduce
Apply wave effect to icicle model with 1-8-1 pattern (alternate nodes selected)
select sine or triangle wave type
Set Scale Height of Wave to 100
Observe the top row of pixels does not render
Add Y Offset incrementally and note that waveform render changes in very coarse and abrupt steps. For instance, the first step occurs at offset 13.

Expected behavior
Waveform should include the top row of pixels.

If you increase the Thickness of Wave parameter eventually you get to the point where two vertical pixels are displayed and the top row begins to appear.

If you apply a Y Offset you can also get the top row to appear but then you loose the bottom row.

Seems like it might be some sort of rounding issue.

Screenshots

I have attached a copy of the sequence used to reproduce the problem. I added an on effect with transparency so you could see the individual pixels of the icicle.

wave effect.xsq.zip

[sslupsky]

This screenshot illustrates what happens when the Mirror Wave option is checked. There is an asymmetry in the rendered waveform.

[sslupsky]

Interestingly, if you set the Thickness of Wave parameter to 0 the mirrored waveform is symmetric:

Also, the non mirrored waveform reaches the maxima:

[sslupsky]

A triangle wave illustrates asymmetry as well. The first screenshot is the mirrored waveform:

And the second is not mirrored: