View3D cropbox

[tiago_marafigo]

Hi there!

I'm trying to create and setup some 3D camera views but can't seem to solve one part of the code. I've created the perspective view and setup the proper direction.

Now I need to resize the view's cropbox to properly fit an element. I've tried a LOT of ways of achieving this, the closest I got looks like this:

//

//view has been already created and adjusted the direction before

//

XYZ cropBoxMin = new XYZ();
XYZ cropBoxMax = new XYZ();

//calculate the opposite angle of the triangle to help generate the 'cone' like view
double horizCO = 1 * Math.Tan(horizAngle);
double vertCO = 1 * Math.Tan(vertAngle);

//set initial point

cropBoxMax = pStartOffseted;
cropBoxMin = pStartOffseted;

//offset points to know directions and distance using 3d view coordinate

cropBoxMax += horizCO * XYZ.BasisX;
cropBoxMax += vertCO * XYZ.BasisY;
cropBoxMax += 1 * XYZ.BasisZ;

cropBoxMin -= horizCO * XYZ.BasisX;
cropBoxMin -= vertCO * XYZ.BasisY;
cropBoxMin -= 2 * XYZ.BasisZ;

//create bounding box and apply max and min

BoundingBoxXYZ bb = new BoundingBoxXYZ();
bb.Max = cropBoxMax;
bb.Min = cropBoxMin;

//create transform from view and apply inverse to bb min and max

Transform tInv = view3d.CropBox.Transform.Inverse;
bb.Max = tInv.OfPoint(bb.Max);
bb.Min = tInv.OfPoint(bb.Min);

 //apply transformed bb to view.cropbox

view3d.CropBox = bb;

The view either gets weird, looking somewhere random, or an exception gets thrown in saying "box is empty".

I'd reaaally appreciate any thoughts and advises!

Thanks!

[matthew_taylor · Accepted solution]

Hi @tiago_marafigo,

You look to be adjusting the points each time instead of just using a component (x, y, or z) of that point if it is greater or lesser.

There is a good example of how to do it here:

http://thebuildingcoder.typepad.com/blog/2009/12/crop-3d-view-to-room.html

[tiago_marafigo · Accepted solution]

---

@matthew_taylor wrote:

Hi @tiago_marafigo,

You look to be adjusting the points each time instead of just using a component (x, y, or z) of that point if it is greater or lesser.

There is a good example of how to do it here:

http://thebuildingcoder.typepad.com/blog/2009/12/crop-3d-view-to-room.html

---

Hi @matthew_taylor, thank you for your input.

I had seen that link before, but decided to look at it again. It turns out that its logic is exactly what I need, just with some adjustments.

I used the same method to retrieve the element geometry and the corner points. I modified from there eliminating duplicated values and also a certain range of values that I knew I didn't need :

//create new list to add all X values
List<double> pX = new List<double>();
foreach (XYZ p in vertices)
{
double dd = p.X;
pX.Add(dd);
}

//remove duplicated values

List<double> uniqueX = pX.Distinct().ToList();
uniqueX.Sort();

//create new list to add values within known range

List<double> xInRange = new List<double>();
foreach (double d in uniqueX)
{
if (d > -1 && d < 1)
xInRange.Add(d);
}

//do something with it

It might be a bit of an abomination in terms of organization and efficiency, but it works. Thanks!