Glitch in hilighting of Faces and Edges

I have noticed a very strange behavior when switching to Edge or Face selection modes in AIS_InteractiveContext.

To see the glitch just open the AISSelect MFC sample, create a Box, switch to Select Edges and move the mouse over the box. The first time it touches an edge it is hilighted correctly, but the next touched edge draws lines toward the center of the coordinate system instead. If you click, it selects the edge and displays it correctly. Next edge touched by the mouse will be correctly hilighted, next one not. AIS_InteractiveContext::Select seems to reset this behavior (that's why the click makes it work again for the next touched edge). AIS_InteractiveContext::Redisplay also corrects this behavior, but it's too expensive to call this method every time the mouse moves.

Now, for faces, the result is that instead of hilighting all the edges that "enclose" the face, it only hilights 1 edge, no matter what. Once again, if you click, it selects and hilights as expected.

I started using OCC since version 6.2 not long ago, and the problem is still there in 6.3.

Any ideas?

Arjan Schouten's picture

No problems here, maybe it is your graphics driver, try installing the latest updates fot your graphic driver

P Dolbey's picture


I agree with Arjan here. I remember having a bunch of similar problems that were fixed by upgrading the driver for an ATI X300 card.


Svetlozar Kostadinov's picture

I've experienced the same problem on my laptop and maybe on the desktop machine (i forgot)

Paul Jimenez's picture

It seems it's going to be the graphics driver. I tried it in another computer and it worked fine. I still need to find the reference for this computer because it rejects the generic Intel driver.


Sharjith Naramparambath's picture

It seems you are not having a 3d graphics card that supports OpenGL like the ones from nvidia or ati. On-board intel graphics is not very much suitable for OpenGL applications like Open Cascade.

N. Sharjith

Arjan Schouten's picture

My DELL Inspiron Laptop graphic driver didn't support OpenGL hardware rendering out of the box.
The problem is that ATI/AMD and NVIDIA cannot provide drivers for there Mobile chip sets because they have to be provided by the original Laptop/Notebook manufacturor.
Luckily, there is a tool called Mobility Modder which mods the ATI desktop drivers so they can be used on Laptops.

Svetlozar Kostadinov's picture

I've got mobile Intel 3100 and it has very bad support for 3d graphics - be it OpenGL or DirectX. Not even close to the Intel's loud advertisements. :(

Paul Jimenez's picture

Intel's OpenGL implementation seems to be problematic with OpenCascade. SiS' implementation isn't that great either. My current solution to all those glitches and application hangs was to compile Mesa ( for Windows and copy the 3 DLLs it produces next to the executable (I also have the OpenCascade DLLs there). The compilation process was straight forward using the Visual C++ files.

It may be a good solution for all those who have problems caused by faulty/buggy/fragile OpenGL implementations from the video vendors.