FAQ were recently updated to Eyeshot version 3.0

	How do I see if Eyeshot Viewport is active?
	When the Eyeshot viewport is active the Coordinate System Icon shows the axis labels XYZ, otherwise it doesn't.

	How do I change the line/arc/ellipse on screen thickness?
	Changing the Entity.LineWeigth property value. This value also affects the entity width during printing. Values less than one are correctly rendered only on paper.

	Is it possible to mark some entities as UNselectable?
	Yes, setting the entity's Selectable property to false.

	How do I make some entities temporary not visible?
	Set the entity's Visible property to false.

	How do I know what OpenGL version I am using?
	Calling the Viewport.OpenglVersion and Viewport.OpenglRenderer properties.

	How do I test my program on a machine without the DDXcoreMSM.msm installed?
	Use the Eyeshot setup program, choose Custom setup type and UNselect all the available features. For your information the /Program Files/devDept Software/Bin folder and relative files will be also installed.

	When should I use prefer Entity.TransformBy() method to Translate() / Rotate() / Scale()?
	They do exactly the same thing: transform your entity vertices. By the way there is one important difference, if you need to apply more than one operation Entity.TransformBy() will be faster because it modifies the entity vertices only once.

	I can move, rotate and scale meshes as long as they are not yet added to the Viewport. After they are added, no action is taken. When I manipulate a Quad, it works fine. What can I do?
	Complex objects need to be regenerated after transformations, try adding a call to Viewport.Entities.Regen().

How do I prevent too many labels to be drawn on screen?

Labels expose the OnScreenPosition property that allow you to know their position on the screen 2D surface. Using this information you can subdivide the screen surface in a grid and prevent multiple labels to be drawn in the same grid cell. The right place to do all of this is the Viewport.DrawOvelay() method that needs to be overridden. Just before calling the base class implementation you will set the specific label Visible property to true/false.

	How can I speed up texture loading?
	Preparing all the texture images with dimensions power of two, like 128x128, 256x256, 512x512, ...

Code generation for property XXX failed. Error was: XXX is unable to convert XXX to System.ComponentModel.Design.Serialization.InstanceDescriptor

This message is Visual Studio error. It happens when Visual Studio loads either two different versions of same assembly or two same versions from different locations. It can be caused by number of different things: make sure that only single build of Eyeshot is referenced, make sure that only single version of component is installed on your machine, make sure that you do not have CopyLocal property set to true if you have installed Eyeshot into the GAC (Global Assembly Cache). Note that Eyeshot is not installed into the GAC by default.

	I am trying to add a multimillion vertices Mesh to the Eyeshot Viewport but I get an OpenGL error related to running out of memory. What can I do?
	Switch to a 64-bit Operating System.

	My texture looks poorly when is applied on the model, why?
	Try setting the Material.MinifyingFunction = Linear.

	How do I change the background color of my TextOnly labels?
	Using the FillColor property.

	How do I draw some entities on a plane different from XY?
	See the Transformations code sample.

	How do I show current FPS (Frame Per Second) rate?
	Setting the Viewport.ShowFps property to true.

	Why I get the WriteAutodesk error: System.Runtime.InteropServices.COMException ... when I use the ViewportProfessional.ReadAutodesk() or WriteAutodesk() methods on Windows Vista 64 bit?
	OpenDWG, the tool Eyeshot uses for reading/writing Autodesk files is not compatible with 64 bit operating systems yet. To use these two methods on 64 bit operating systems set the Platform target to 'x86' in your Visual Studio project properties.

	Why the shadow is not visible on some machines?
	The new Eyeshot shadow is implemented using OpenGL Shading Language. Generally the minimum OpenGL version supporting it is version 2.0.

	How do I know if Eyeshot is using hardware acceleration on a specific machine?
	Check the return value of the Viewport.IsHardwareAccelerated property.

Why shouldn't I use the Viewport.SaveFile()/OpenFile() methods to store my models?

These commands can be very attractive to save and load models in you program but have a serious pitfall: they are based on standard .NET serialization. This means that any change on the Eyeshot binaries (dll versions, dll names, type names, etc.) will invalidate all your existing files. We strongly recommend to implement your own file format (simply writing entities properties and recreating entities during file loading) if you need continuity between different Eyeshot DLL versions. Another option can be to use one of the standard format supported (DWG/DXF/IGES) where applicable.

	When should I call Regen() after transforming my entity?
	viewport.Entities.Regen() is necessary only if the entity is already in the master entity collection (viewport.Entities). If not, it will be called automatically by Eyeshot.

	Why do I get the GL_INVALID_VALUE exception?
	The main reason is that you are probably adding the same entity to two different viewports or to the same viewport.Entities and Block collections. This is not allowed by design. Use the Entity.Clone() method to get a valid copy of your entity.

	When I change coordinate system icon axis color at runtime nothing happens, what should I do?
	You need to call the myViewport.CompileUserInterfaceElements() and myViewport.Invalidate() methods to see the changes.

	Is it possible to use Eyeshot in a WPF form?
	The short answer is yes using the WindowsFormHost control. The long answer is that after many tests we concluded that there is no reason for doing it. If you really want to use WPF controls is more effective to create a Windows Forms application and insert a WPF region that contains WPF controls. We strongly recommend to read the following article on the subject: WPF vs Windows Forms.

	Why Eyeshot is so slow on some machines?
	3D graphics comes not for free and some machines with legacy or very cheap graphics adapters run OpenGL in software emulation.

	How do I add entities to the viewport from a different process?
	Adding entities from a different process is not allowed. You can however fill a separate List in your multi-threaded application and once finished add all these entities to the viewport in one operation using the mainViewport.Entities.AddRange() method.

	Why I cannot hide a semi-transparent entity setting the Visible property to false?
	Transparency involves the need of a geometry pre-processing every time the model changes. Considering that this is true also for shadow and bounding box we recommend to call the viewport.Entities.UpdateBoundingBox() method every time you need to update the visibility status of a semi-transparent entity.

	Why some of my entities are drawn black in Rendered display mode?
	In Rendered display mode the Entity.Material.Diffuse color is used. Please check it is not null/Nothing for your entity. In the case that Entity.ColorMethod is set to byLayer, the Layer.Material.Diffuse will be used.

Why I get a System.StackOverflowException when I change the color of my entitiy to semi-transparent?

Semi-transparent entities require a pre-processing step that doesn't check for invalid triangles. It is very likely that your geometry contains one or more invalid triangles. One solution to this problem can be to check the area of each entity's triangle using the devDept.Eyeshot.Entities.Triangle.Area() method and remove the invalid ones before adding the entity to the viewport master entity collection.

	How can I improve the frame rate when drawing heavy semi-transparent objects?
	Try setting the Viewport.Entities.FrontFacingOnly = true. This prevents back-facing semi-transparent triangles to be drawn, increasing considerably the frame rate.