Preview Image

Rhino Developer
, ,
1

Hi,

I’m attempting to create preview images of individual pieces of geometry. Based on other posts here, I think this should work, but it doesn’t:

using System;
using System.IO;
using System.Linq;
using Rhino;
using Rhino.Commands;
using Rhino.Display;

namespace Dev.Common
{
    [
        System.Runtime.InteropServices.Guid("e58debff-8f45-4a1c-8b12-32ed2fe44363"),
        CommandStyle(Style.ScriptRunner)
    ]
    public class DevCommand : Command
    {
        public DevCommand()
        {
            // Rhino only creates one instance of each command class defined in a
            // plug-in, so it is safe to store a refence in a static property.
            Instance = this;
        }

        ///<summary>The only instance of this command.</summary>
        public static DevCommand Instance { get; private set; }

        public override string EnglishName => "MyDevCommand";

        protected override Result RunCommand(Rhino.RhinoDoc doc, RunMode mode)
        {
            // Assumes at least one object is selected.
            var selectedId = doc.Objects.GetSelectedObjects(false, false).Select(o => o.Id).First();

            if (GenerateImage(selectedId, doc))
            {
                RhinoApp.WriteLine("Created image");
                return Result.Success;
            } else
            {
                RhinoApp.WriteLine("Failed creating image");
                return Result.Failure;
            }
        }

        private static bool GenerateImage(Guid guid, RhinoDoc doc)
        {
            try
            {
                // Create a new RhinoView
                RhinoView rhinoView = doc.Views.Add(
                    "Preview",
                    DefinedViewportProjection.Perspective,
                    new System.Drawing.Rectangle(0, 0, 512, 512),
                    true
                );

                // Get a tmp file path
                var filePath = Path.Combine(Path.GetTempFileName(), ".bmp");

                // Zoom Selected
                var zoomSuccess = rhinoView.MainViewport.ZoomExtentsSelected();

                // Make sure the view is updated..
                rhinoView.Redraw();

                // Save a preview image
                return rhinoView.CreateShadedPreviewImage(filePath, new System.Drawing.Size(512, 512), true, false, false);
            } finally
            {
                // Clean up the view
                var views = doc.Views.Where(v => v.MainViewport.Name == "Preview").ToList();
                foreach (var v in views)
                {
                    v.Close();
                }
            }
        }
    }
}

Can anyone spot what I am doing wrong here? I’ve tried with .jpeg, .png, and without extension as well. I’m on Mac, and Rhino 6.

Thanks,
Aske

2

Hi @aske,

See if this SDK sample is helpful:

SampleCsViewCapture.cs

– Dale

3

Hi @dale

Thanks! I already had looked and used that example but can’t get it to work properly. Also, hijacking the ActiveView seems dirty: what if it’s a Layout view? I guess I could restore the previous settings for normal views, but it still feels a bit iffy.

This is what I’ve tried:

        private static bool GenerateImage3(Guid guid, RhinoDoc doc)
        {
            // What if ActiveView is a Layout?
            RhinoView rhinoView = doc.Views.ActiveView;

            // Get a tmp file path
            var filePath = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.png");
            RhinoApp.WriteLine(filePath);
            // Zoom Selected
            var zoomSuccess = rhinoView.MainViewport.ZoomExtentsSelected();

            rhinoView.MainViewport.DisplayMode = DisplayModeDescription.GetDisplayMode(DisplayModeDescription.ShadedId);

            // Make sure the view is updated..
            rhinoView.Redraw();

            var view_capture = new ViewCapture
            {
                Width = rhinoView.ActiveViewport.Size.Width,
                Height = rhinoView.ActiveViewport.Size.Height,
                ScaleScreenItems = false,
                DrawAxes = false,
                DrawGrid = false,
                DrawGridAxes = false,
                TransparentBackground = true
            };

            var bitmap = view_capture.CaptureToBitmap(rhinoView);
            if (null != bitmap)
            {
                bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);
                return true;
            }
            else
            {
                return false;
            }
        }

The shaded mode is not respected. It only changes after the command has run. On DetailViews there is a CommitViewportChanges method, but I can’t find anything similar on RhinoView. Is there anything I can do to force a view/viewport update?

Thanks,

4

I ended up giving up.
I wrote a glTF-binary exporter instead, and will use that for previews instead. That was easier than getting consistent results out of Rhino. I’m probably doing something wrong somewhere since it’s that hard.

5

Hi @aske,

The sample that I posted does work if the active view is a layout, or RhinoPageView, at least on Windows. Your using a Mac, right?

– Dale

6

I’m on a Mac yes.
The sample you posted works. Both on V6 and V7.