Problems with a numeric slide control.

[Tera-Engineer]

Hello Everyone,

First off thank you in advance for your help.  Below is a description of my problem.

I am trying to use a numeric slide control to adjust my z-scale on an intensity graph.  I am using several images to create one high dynamic range (HDR) image and having a slide for my z-scale to adjust it on the fly is much easier to use then manually punching in the numbers.  My problem is that I am covering about 7 or 8 orders of magnitude from min to max in my z-scale.  So in order to see all of the data that is contained in the HDR image I need the slide to cover the full range of min to max value of the image.

When I set the slide scale mapping to logarithmic so I can get more seperation in the values and see and scale through the low end easier, the scale is auto truncated to onle 3 orders of magnitude.  This doesn't work for me, is there a way to fix this?

Example:

When I set the scale on the slide to be the min and max of the z-scale on the intensity graph.  I get values of the z-scale being 2.47E+7 for the max, and 0 for the min.  The max value on the slide scale = 2.47E+7 and the min value = 2.47E+4.  I need the min value to be 0.

Thank you again,
~Daniel DeWitte

[johnsold · Accepted solution]

Daniel,

Log(0) = ?  Exercise left for student.

Try setting the Z Scale.Minimum property to some small positive value like 0.1 or 0.001.

I created a slider and a numeric control.  The slider minimum is set to zero. The numeric control is an integer ranging from 0 to 20. The slider maximum is 10^(numeric). The slider is wired to the Intensity graph ZScale.Maximum property node.

Works fine.

Of course I would put the changes in an event structure rather than writing to the property nodes on every iteration of the loop.

Lynn

[Tera-Engineer]

Lynn,

Thank you for your help, that was exactly the problem.  The only adjustment that I made is that I hard wired the Z-scale min on the slide control to be .001 as well.  I was more worried about displaying the data then looking at the raw equation of what I was asking the computer to resolve, log(0) is undefined, kind of bad for me when I have a bachelor's  in physics.  It was just one of those things that wasn't even considered.

Thanks again,

~Dan

[johnsold]

It is easy to get so focused on the details of a program that you forget to think about what it is doing.  I won't tell your professors.  All you need to worry about is whether they read the Forum.

Lynn