Hello 
I’m working on a C# plugin which contains custom data types some being displayed in the viewport.
For example, there’s a custom data type called GH_Support which implements GH_GeometrcGoo. When created with a component GH_Supports are displayed like this:
I created a custom floating parameter which implements GH_PersistentGeometryParam<GH_Support>. This floating parameter seems to work well except for the preview … The data inside is not displayed in the Rhino viewport.
I suspect this is linked to the lack of Display button in the menu but I can’t add it …
Does anyone have an idea on how to display data within the parameter ?
Thank you !
PS: here are the files containing the C# definition ;
MyPlugin.zip (360.7 KB)
You will have to implement the IGH_PreviewObject interface in your parameter to enable previews on it.
Hello @DavidRutten, thank you for your quick answer !
I tried to implement IGH_PreviewObject but I’m struggling a bit to be honnest. Here’s my try :
public void DrawViewportWires(IGH_PreviewArgs args)
{
foreach (GH_Support data in VolatileData.AllData(true) )
{
data.DrawViewportWires((GH_PreviewWireArgs)args );
}
foreach (GH_Support data in PersistentData.AllData(true))
{
data.DrawViewportWires((GH_PreviewWireArgs) args);
}
}
public void DrawViewportMeshes(IGH_PreviewArgs args)
{
foreach (GH_Support data in VolatileData.AllData(true))
{
data.DrawViewportMeshes((GH_PreviewMeshArgs) args);
}
foreach (GH_Support data in PersistentData.AllData(true))
{
data.DrawViewportMeshes((GH_PreviewMeshArgs) args);
}
}
public bool Hidden { get; set; }
public bool IsPreviewCapable { get { return true; } }
Firstly, I suppose that I can create auto-property for Hidden.
Then, as GH_Support can be previewed, IsPreviewCapable is always true ?
Eventually, I tried to implement DrawViewportWires(IGH_PreviewArgs args) and DrawViewportMeshes(IGH_PreviewArgs args) using GH_Support methods as I suppose that its GH_PreviewWireArgs(GH_PreviewWireArgs args) and GH_PreviewMeshArgs(GH_PreviewMeshArgs args) methods work as intended.
In the end, the preview button is present but nothing is displayed in the viewport … Do you have any clue of what’s wrong ?
Sorry to Necro this post. But I have come across the exact same problem, and rather then repost something, I and am wondering if this has been resolved? Or if Rutten could perhaps give more direction?
I’ve tried implementing IGH_PreviewData and IGH_PreviewObject and neither of them seem to actually get the component to draw
Any help would be really helpful.
public class TestPoint3dParameter : GH_PersistentGeometryParam<GH_TestPoint3d>, IGH_PreviewObject, IGH_PreviewData
{
public bool Hidden { get; set; }
public bool IsPreviewCapable { get; }
public void DrawViewportMeshes(GH_PreviewMeshArgs args)
{
}
public RG.BoundingBox ClippingBox
{
get
{
List<RG.Point3d> points = new List<RG.Point3d>();
foreach (GH_TestPoint3d data in VolatileData.AllData(true))
points.Add(data.Value.ToRhino());
foreach (GH_TestPoint3d data in PersistentData.AllData(true))
points.Add(data.Value.ToRhino());
return new RG.BoundingBox(points.ToArray());
}
}
public void DrawViewportWires(GH_PreviewWireArgs args)
{
foreach (GH_TestPoint3d data in VolatileData.AllData(true))
data.DrawViewportWires((GH_PreviewWireArgs)args);
foreach (GH_TestPoint3d data in PersistentData.AllData(true))
data.DrawViewportWires((GH_PreviewWireArgs)args);
}
public void DrawViewportWires(IGH_PreviewArgs args)
{
GH_PreviewWireArgs wireArgs = new GH_PreviewWireArgs(args.Display.Viewport, args.Display, args.WireColour, args.DefaultCurveThickness);
foreach (GH_TestPoint3d data in VolatileData.AllData(true))
data.DrawViewportWires(wireArgs);
foreach (GH_TestPoint3d data in PersistentData.AllData(true))
data.DrawViewportWires(wireArgs);
}
public void DrawViewportMeshes(IGH_PreviewArgs args) => throw new NotImplementedException();
public override bool AppendMenuItems(ToolStripDropDown menu)
{
Menu_AppendPreviewItem(menu);
return base.AppendMenuItems(menu);
}
}
}
