View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0022034 | Open CASCADE | OCCT:Visualization | public | 2010-09-29 15:52 | 2010-09-29 19:24 |
| Reporter | Assigned To | bugmaster | |||
| Priority | normal | Severity | trivial | ||
| Status | closed | Resolution | unable to reproduce | ||
| OS | All | ||||
| Summary | 0022034: Display of mesh with using MeshVS with VBO objects is extremely slow | ||||
| Description | As experienced during testing OCCT 6.4.0 beta in LH3D-3H software (RINA), when VBO is enabled, visualization of big mesh (138070 1d elements and 153240 2d elements) becomes extremely slow (it is just impossible to wait). The time in this case is spent in graphics driver, with stack traced back to the cycle found in file OpenGl_PrimitiveArray.cxx on line 641. It seems that here each 1d element is displayed by separate call to method glDrawArrays(). However, the same occurs when VBO objects are not used, but in the latter case display is fast. The problem is to be investigated. Possible solution is to improve logic of choice of using or not VBO found on line 538 of the above said file, so as to use non-VBO variant in cases when VBO would not be efficient. As a temporary solution for OCCT 6.4.0, it is proposed to set default mode of using VBO to False. See proposed correction attached. It is necessary to correct Release Notes saying that VBO is OFF by default, and describe how VBO can be enabled (and check this). | ||||
| Tags | No tags attached. | ||||
| Test case number | |||||