Issue 75154 - 3D shapes lose color at certain angle or rotation
Summary: 3D shapes lose color at certain angle or rotation
Alias: None
Product: Impress
Classification: Application
Component: ui (show other issues)
Version: OOo 2.2 RC2
Hardware: All All
: P3 Trivial (vote)
Target Milestone: ---
Assignee: AOO issues mailing list
QA Contact:
Depends on:
Reported: 2007-03-06 13:07 UTC by raindrops
Modified: 2013-08-07 15:21 UTC (History)
2 users (show)

See Also:
Issue Type: DEFECT
Latest Confirmation in: ---
Developer Difficulty: ---

Screenshots of a rotated shape (18.20 KB, application/vnd.oasis.opendocument.text)
2007-03-06 13:08 UTC, raindrops
no flags Details
jpg showing 3Deffects window in Draw (56.47 KB, image/jpeg)
2007-03-07 10:01 UTC, cno
no flags Details
In-depth analysis of rotation of 3D-shape (187.95 KB, application/vnd.oasis.opendocument.text)
2007-03-09 13:58 UTC, raindrops
no flags Details

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Description raindrops 2007-03-06 13:07:28 UTC
When 3D shapes are rotated, at certain angle, a face loses all color, and
becomes white.

The attached file shows screenshots with a yellow background.

Desired: The face should not lose all color.
Comment 1 raindrops 2007-03-06 13:08:14 UTC
Created attachment 43544 [details]
Screenshots of a rotated shape
Comment 2 wolframgarten 2007-03-06 13:41:30 UTC
Reproducible. Reassigned.
Comment 3 cno 2007-03-07 08:25:05 UTC

The window 3D effects from the contextmenu, has a tab with a light bulb.
Playing with that gives posibility to adjust colors.
Does that give a solution?
Comment 4 raindrops 2007-03-07 09:39:03 UTC
You mean the "Extrusion light" window? That is a separate control, which changes
only the angle of the incident light. I am referring to rotating the object itself.

So changing the light is not the correct solution.

BTW I have shown only the edge (thickness) of the 3D shape having this loss of
color. But the same thing happens for even the main face of a shape. When that
happens, the shape loses color for a very wide rotation angle.
Comment 5 cno 2007-03-07 09:59:58 UTC
the window I mean is showed in next attachment
Comment 6 cno 2007-03-07 10:01:12 UTC
Created attachment 43571 [details]
jpg showing 3Deffects window in Draw
Comment 7 Armin Le Grand 2007-03-07 10:22:58 UTC
AW: You are both right, but talking about different things. We have two 3d
UI-modes now, thanks to the MS-compatible AutoShapes 3D stuff which also mimic
the UI for that. It is different to convert a draw object to 3D compared with a
AutoShape (for which this bug is).

Explanation is pretty simple: The object does not 'lose' color, but the plane in
question has only one plane normal (is not interpolated to mimic the non-really
3d stuff from ms). The lighting equation is calculated for that normal. If that
normal points to the light source, it gets a hilight effect which ends in
returning pure hilight color of thatlight source. Per default the first light
source has a hilight activated.

AW->SJ: Please check if AutoShape ion question looks different with ms. If Yes,
it is necessary to switch off the hilight for light source 1 or (alternative)
use light source 2 by default where it is off by default already.
Comment 8 raindrops 2007-03-07 12:20:50 UTC
The shape does not reflect that much of a "shine" in MS Office: The brightest
part of the 3D shape is only a little lighter than the color of its non-3D
(plain) equivalent. 

In OOo, the highlight is too bright(it makes the object pure white at that
spot), which not natural.
Comment 9 raindrops 2007-03-07 12:37:09 UTC
The same correction should be applied to the other GUI pointed out by cornouws.
(See the blue globe in his screenshot: The top part of the globe is white; which
is exactly the same issue)
Comment 10 raindrops 2007-03-09 13:58:45 UTC
Created attachment 43619 [details]
In-depth analysis of rotation of 3D-shape
Comment 11 raindrops 2007-03-09 14:17:13 UTC
AW and SJ,

I have attached a sample about what happens with OpenOffice. As demonstrated,
there are in fact several issues:

1. Compared to MS Office, OpenOffice uses a much wider range of colors to
distinguish shadows from highlights. As a result, the RGB values of the color
quickly reach 00 or FF. 

On the other hand, MS Office uses a much smaller range, so it can handle more
"plain shape" colors, even when they are much closer to saturation (FF).

2. Even when any of the RGB reaches the end of range (00 or FF), OpenOffice
continues to change the remaining color. As a result, the shade of the color

MS Office uses the same shade for all surfaces.

3. The color does not change linearly with the plane's angle vis-a-vis light source.