View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0027716 | Community | OCCT:Visualization | public | 2016-07-27 14:45 | 2018-03-13 16:14 |
| Reporter | Roman Lygin | Assigned To | bugmaster | ||
| Priority | low | Severity | minor | ||
| Status | closed | Resolution | duplicate | ||
| Product Version | 7.0.0 | ||||
| Target Version | 7.2.0 | Fixed in Version | 7.2.0 | ||
| Summary | 0027716: Visualization - incorrect treatment of multiple transparent objects in 3D view | ||||
| Description | When several objects in 3D view have transparency set then display results gets weird - see screenshot. At the same time, when only one object has transparency then everything seems to be in order. My guess is that this may have something to do with simple setting display priority to maximum (ten) in AIS_Shape::SetTransparency(). That is, when multiple objects have the same priority the result is getting incrrect. | ||||
| Steps To Reproduce | pload MODELING VISUALIZATION box b 100 200 300 box bb 50 10 20 100 150 200 bop b bb bopcut r vclear vinit View1 vsetgradientbg 180 200 255 180 180 180 2 vsetdispmode 1 vdisplay r bb vsetcolor r RED vsettransparency r 0.75 vsettransparency bb 0.5 vaxo vfit vrotate 0 5 0 vfit Original test case: box b 100 200 300 box bb 50 10 20 100 150 200 bop b bb bopcut r vinit vdisplay r bb vsetcolor r RED vsettranspar r 0.75 #OK vsettranspar bb 0.5 #result gets weird | ||||
| Tags | No tags attached. | ||||
| Test case number | Not required | ||||
| duplicate of | 0027925 | closed | bugmaster | Open CASCADE | Visualization - implement order-independent transparency algorithm within rasterization rendering |
| has duplicate | 0028155 | closed | bugmaster | Community | Visual artefacts when setting transparency |
| has duplicate | 0028253 | closed | bugmaster | Community | Incorrect treatment of transparency if a spline face overlaps itself in 3D view |
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screenshot_draw.png (30,971 bytes) |
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Dear Roman, this behavior is a known limitation of current implementation of transparent object in OCCT viewer. In contrast to traditional rasterization pipeline, Ray-Tracing in OCCT viewer supports proper order-independent transparency. Alternatively, application might sort transparent objects themselves to workaround artifacts in most obvious cases. There are many various rendering techniques intended to solve this problem (to some degree) for rasterization approach. You are welcome to our support services if you would like us implementing some of them in OCCT. |
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transparency_raster.png (5,122 bytes) |
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transparency_raytrace.png (4,775 bytes) |
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Dear Kirill, Thank you for the explanation. We will take that into account. |
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Problem described in issue is reproduced on current state of OCCT. |
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Please close issue as duplicate of 0027925. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2016-07-27 14:45 | Roman Lygin | New Issue | |
| 2016-07-27 14:45 | Roman Lygin | Assigned To | => kgv |
| 2016-07-27 14:45 | Roman Lygin | File Added: screenshot_draw.png | |
| 2016-07-27 15:41 | kgv | Note Added: 0056245 | |
| 2016-07-27 15:41 | kgv | Priority | normal => low |
| 2016-07-27 15:41 | kgv | Resolution | open => no change required |
| 2016-07-27 15:41 | kgv | Target Version | 7.1.0 => Unscheduled |
| 2016-07-27 15:41 | kgv | Summary | Incorrect treatment of multiple transparent objects in 3D view => Visualization - incorrect treatment of multiple transparent objects in 3D view |
| 2016-07-27 15:41 | kgv | Steps to Reproduce Updated | |
| 2016-07-27 15:41 | kgv | File Added: transparency_raster.png | |
| 2016-07-27 15:42 | kgv | File Added: transparency_raytrace.png | |
| 2016-07-27 15:42 | kgv | Note Edited: 0056245 | |
| 2016-07-27 15:42 | kgv | Note Edited: 0056245 | |
| 2016-07-27 16:04 | Roman Lygin | Note Added: 0056247 | |
| 2016-10-03 14:08 | kgv | Relationship added | related to 0027925 |
| 2016-11-25 16:56 | kgv | Relationship added | has duplicate 0028155 |
| 2016-12-20 16:32 | kgv | Relationship added | has duplicate 0028253 |
| 2017-08-18 12:11 |
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Test case number | => bugs vis bug27716 |
| 2017-08-18 12:11 |
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Note Added: 0069566 | |
| 2017-08-18 13:11 |
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Test case number | bugs vis bug27716 => Not required |
| 2018-03-13 14:40 | kgv | Note Added: 0074433 | |
| 2018-03-13 14:40 | kgv | Assigned To | kgv => bugmaster |
| 2018-03-13 14:40 | kgv | Status | new => feedback |
| 2018-03-13 14:40 | kgv | Resolution | no change required => duplicate |
| 2018-03-13 14:40 | kgv | Fixed in Version | => 7.2.0 |
| 2018-03-13 14:40 | kgv | Target Version | Unscheduled => 7.2.0 |
| 2018-03-13 14:41 | kgv | Relationship replaced | duplicate of 0027925 |
| 2018-03-13 16:14 | bugmaster | Status | feedback => closed |
