Why do I see residual mouse trails (visual artifacts) left behind when moving things in the drawing pane?

Applies To
Product(s): WaterGEMS, WaterCAD, HAMMER, StormCAD, SewerCAD
SewerGEMS, CivilStorm, StormCAD, PondPack
Version(s): 10.00.xx.xx, 08.xx.xx.xx
Area: Modeling
Original Author: Mark Pachlhofer, Bentley Technical Support Group

Problem Description

When I move my mouse around I see "ghost" trails remaining in the drawing pane when zooming, drawing a box around elements or connecting a pipe. Examples:





This is a common issue with certain video cards and graphics hardware

Steps to Resolve

Option 1: If you are using a CONNECT Edition or V8i version of the software

  1. Go to Tools > More > Options
  2. On the Global tab locate the "Use Accelerated Redraw" check box and if it's checked uncheck it. If it's not checked then check it. Basically, you will need to do the opposite of whatever is already there.
  3. Click Ok to close the window and accept the changes
  4. See "Background" section below for more information on why this helps.

Option 2: If you are using a V8 XM version of the software 

If you are using Windows XP, try the following: - Turn down video acceleration by going to start > control panel > display > settings > advanced > troubleshooting - Switch the buffering and vertical synchronization settings in your video card`s advanced options - Update your video card drivers from the manufacturer`s website

If you are using Windows 7, please try editing your video card`s setting and enable Anti-aliasing (e.g. 2x, 4x, etc as opposed to None or Application Controlled).

If this does not help and you have the V8 XM generation version of the software (example: StormCAD V8 XM, WaterGEMS V8 XM), then try these steps: 1) Make sure the program is closed and then open up windows explorer 2) Browse to C:\Documents and Settings\\Application Data\Bentley\\8\ (where "" is the name of the user that you are logged in as and "" is the program you are experiencing this problem in.

  1. NOTE: If you have Windows Vista, this file is located under: C:\Users\<username>\AppData\Roaming\Bentley\<software>\8\

    3) Right click on Haestad.Framework.Application.GlobalUserOptions.xml and choose to edit. It should open in Notepad. 4) Locate the entry near the bottom called "AllowPartialRedraw="true"". Change "true" to "false", save and close the file. 5) Reopen the program and try the zoom tool

    Note that you may need to have the latest build of the V8 XM generation for this option to be available.


The problem that causes some video cards to have this issue is not really a problem at all, but rather a feature of some video cards called Triple Buffering. Without going into too much technical detail, the program basically uses a special technique to speed up the rendering of our so-called "rubber-banding lines." These are the lines that follow the cursor and are redrawn on screen whenever the cursor is moved (e.g. selection rectangle, laying out a pipe, etc.). However, this technique can have the side effect of leaving "trails" on the drawing window during these operations when triple buffering is enabled on the video card.

Unchecking the "use accelerated redraw" option tells the application that, in those cases where a "rubber-banding line" is being drawn, it should use a different technique to draw it that works better with triple buffered video cards. Unchecking this option does not mean that software acceleration is being used to render the model. The application still uses hardware acceleration and takes full advantage of your video card. It simply means that it will choose a better technique to draw with your triple buffered video card.

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