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Teigha Kernel: OdGsView Interactivity Mode

Interactivity mode is a new feature of the Teigha graphics system . It allows for automatic interruption of the drawing process if the process is taking a long time. Of course in this case the drawing will not be drawn completely, but this feature can be useful for multiple consecutive redraws when the result of the intermediate redraw is not so important.

rendering Example sources

Frequently Asked: How can I solve a large coordinates problem during geometry display and graphics cache auto-regeneration?

Vectorization modules based on DirectX/OpenGL graphics APIs ("WinOpenGL.txv", "WinDirectX.txv" and "WinGLES2.txv") don’t render geometry accurately for large coordinates due to hardware limitations.

rendering getting started

Frequently Asked: How do I disable/enable lights inside blocks?

By default, displaying light sources inside block inserts is enabled and Teigha rendering takes them into account. But large drawings can contain many light sources which can seriously downgrade rendering performance.

rendering getting started

Frequently Asked: How can I modify drawn colors from my application during display?

Sometimes rendering applications require a modification to drawn colors during rendering without a long update of geometry cache.

rendering getting started

Graphic System Overlays

Complex graphic scenes with a large number of elements are sometimes drawn slowly. In this case, dynamic graphic elements (such as cursors, grip/snap points, selection rectangles, user interface elements, and so on) are drawn slowly too because to correctly combine graphic scenes and dynamic graphic elements, the renderer must redraw all underlying scene elements.

rendering performance Example

Hatch Types and Exporting to PDF

Sometimes ODA members ask about exporting hatches and why a resulting .pdf file is very slow to open or why the quality of exported hatches is poor. This article explains a few things about hatches and exporting them to PDF.

There are three main types of hatches in .dwg files:

export rendering

Teigha Kernel: OdGsModel invalidation methods

Teigha’s graphics system allows graphical objects to be cached to increase the performance. However there are conditions when cached data quality becomes too rough (for example, during zooming), so Teigha provides several methods of invalidation (regeneration) for this data.

video rendering

Adding an Alpha Channel to a Raster Image

Previously Teigha developers could add an alpha channel to a raster image using the OdGiRasterImage::convert method and subsequently cutting off the background color. However, using the new OdGiRasterImage wrapper OdGiRasterImageAlphaChannelAdder simplifies this task.

Alpha channel rendering

Planar clipping sections generation for custom entities

Teigha vectorization framework provides ability to clip geometry inside rendered scene, using OdGiOrthoClipperEx conveyor node which is always available inside default geometry vectorization conveyor.

rendering Example