Perspective mode and Zoom values greater than 1.0

[Measure]

Hello,

My colleague and I are working on our code - vb6 and 5559 build.

We have noticed an issue under 2 conditions:

1) IView_DG - SetProjectType(eProjectionTypeDgPerspective)
2) IView_DG - Zoom(1.5)

If the zoom is set to a value greater than 1.0 in Perspective mode, the result is an inversion in the View Frustrum (confirmed with Birds Eye View).
When the View Frustrum has an inversion, the 3D surfaces of the model no longer updates when the user uses the mouse to orbit. The lighting and entities like text continue to update. Very odd behavior.

If you use the mouse wheel, it will suddenly correct the View Frustrum and behavior will return to normal.

I think this is a bug, but I am not sure...
Video of behavior: https://somup.com/cTnTb97iO0

Simple code to illustrate the case:
Private Sub Form_Load()
'DG structures
Dim MyContext As IContext_DG
Dim MyModel3D As IModel_DG
Dim MyObjGen3D As IObjectGenerator_DG
Dim MyView3D As IView_DG
' high-level object creation
Set MyModel3D = MyKernelCAD.GetModel()
Set MyView3D = MyKernelCAD.GetView()
Set MyObjGen3D = MyModel3D
Set MyContext = MyView3D.GetContext

'Create a cylinder
Dim cylinder As IEntity_DG
Dim Builder As IStdShape_DG
'Create a object builder
Set Builder = MyObjGen3D.Create("IStdShape_DG")
Set cylinder = Builder.cylinder(5, 8, 10)
Call MyModel3D.AddEntity(cylinder)

Call MyView3D.SetProjectionType(eProjectionTypeDgPerspective)
Call MyView3D.Reset(False, False)
Call MyView3D.Zoom(1.5)
Call MyKernelCAD.UpdateView
End Sub

ZIP file with VBP and form, download: https://www.dropbox.com/t/nYXHJjjFJ7pnM0T5


Thank you for any help you can provide.

-Adam

[Mike Zubovic]

Hello Adam
Thank you for reporting.
We are looking into this.
Regards

[Mike Zubovic]

We have reproduced this in the VB .NET Zoom sample.
It should not take long to fix.
C++ version works OK.
Thanks

[Measure]

Thank you guys, glad it was a real issue and not something I was doing incorrectly.

For now, we are setting Zoom to 1.0 to avoid the issue.

[Mike Zubovic]

We just have posted a fix in 5560 update. The sample works OK with it.
Thanks again for reporting.