Render To Off-screen and SUN Enabling

By Madhukar Moogala

We will discuss few workarounds to tackle the problem with the creation of an off-screen View in .NET,

For C++ interested user, following comprehensive sample should help.

Problem 1:

The problem is that the off-screen view that I have to create looks as a “mirror” or “upside down” of the initial view that i want to render.

Workaround: Currently .NET API gives in-correct results, to work around the behaviour, use

using (Bitmap bitmap = offscreenView.RenderToImage(mySettings, myRectangle))                     {                     if (File.Exists("D:\Temp\RenderTestImage.Jpg"))                         File.Delete("D:\Temp\RenderTestImage.Jpg");                     bitmap.RotateFlip(RotateFlipType.Rotate180FlipX);                     bitmap.Save("D:\Temp\RenderTestImage.Jpg", System.Drawing.Imaging.ImageFormat.Jpeg);                     }

Problem 2:

How to enable the SUN for my off-screen view.

public void RND()         {         Document acDoc = Application.DocumentManager.MdiActiveDocument;         Database acDb = acDoc.Database;         Editor ed = acDoc.Editor;         /*Turn on SUN*/      //   Application.SetSystemVariable("SUNSTATUS", 1);         ViewportTableRecord vport = null;         Sun sun = new Sun();         sun.IsOn = true;         using (Transaction acTrans = acDb.TransactionManager.StartTransaction())             {             vport = (ViewportTableRecord)acTrans.GetObject(acDoc.Editor.ActiveViewportId, OpenMode.ForWrite);             vport.SetSun(sun);             acTrans.Commit();             }         Autodesk.AutoCAD.Geometry.Point2d myScreenSize = (Point2d)Application.GetSystemVariable("screensize");         double myWidth = myScreenSize.X;         double myHeight = myScreenSize.Y;         if (File.Exists("D:\Temp\RndImage.bmp"))             File.Delete("D:\Temp\RndImage.bmp");         ed.Command("_render", "", "render", myWidth.ToString(), myHeight.ToString(), "yes", "D:\Temp\RndImage.bmp");         ed.Command("RENDERWINDOWCLOSE");           }

I have not used renderToImage API, as of now, when SUN is enabled, rendering on off-screen does not display the effects of Sun, hence above workaround is proposed now.