[Bug] r2614: "restore natural slope" results in wrong offset

Topic: [Bug] r2614: "restore natural slope" results in wrong offset (Read 12751 times) previous topic - next topic

[Bug] r2614: "restore natural slope" results in wrong offset

August 24, 2009, 10:40:22 pm

(Not a new bug; tested with Pak64; couldn't find a matching topic)

- find a city building that is built onto a natural slope (using a basement)
- delete this building => basement remains (<-actual bug? separate bug?)
- use tool "restore natural slope" on the tile => natural slope is one level too high

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #1 – August 25, 2009, 06:53:54 am

This bug was introduced by r2544. By reverting the changes in this case, one can fix this bug:

Code: [Select]

Index: simwerkz.cc
===================================================================
--- simwerkz.cc (revision 2614)
+++ simwerkz.cc (working copy)
@@ -915,8 +915,9 @@
 
                if(new_slope == RESTORE_SLOPE) {
                        // prissi: special action: set to natural slope
-                       new_pos = pos;
-                       slope_this = welt->calc_natural_slope(pos.get_2d());
+                       koord pos2d = pos.get_2d();
+                       new_pos = koord3d( pos2d ,welt->min_hgt( pos2d ));
+                       slope_this = welt->calc_natural_slope( pos2d );
                        DBG_MESSAGE("natural_slope","%i",slope_this);
                }
                else {

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #2 – August 25, 2009, 01:24:04 pm

[off-topic]
Root problem for restore natural slope is that we can use many layers artificial slope.
For example, if we build a big mountain with raise land tool, and dig with only artificial slope, all tile still remember the mountain height and want to restore it.

I made a test case.
- Load saved game
- Select lower land tool
- Move cursor to (43,30,5)
- Click

This makes strange.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #3 – August 25, 2009, 01:47:40 pm

:award: really awesome bug

no idea how to fix this.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #4 – August 25, 2009, 02:01:46 pm

Wouldn't it be more logical to "restore" terrain to closest smooth shape rather than to old configuration? The picture shows rather clearly how wrong it can be.

Just my 2c. I'm not coding

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #5 – September 16, 2009, 12:23:08 am

Testing with r2645 nightly (pak64 and pak128): the described bug also occurs with self-made artificial slopes and those from curiosity buildings etc..

Furthermore: when I use the artificial slope tools to lower or heighten flat land by one level, it cannot be undone with "restore natural slope". If the underlying level is water, the error message is "No suitable ground!", otherwise no message occurs.

EDIT:
Restoring after replacing a slope - that resides above other slopes - by a higher artificial one is also not possible. The error message is about maximum height difference.

The problems with restoring in case of increased height may be due to impossible selection of the tile with the cursor.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #6 – September 16, 2009, 07:09:37 am

The problem with this bug (and other bug reports for this issue) is that there are two (independent to some degree) ways of handling slopes. One that stores the height of each grid point and is made for the use with for raise / lower tool. Another one that stores the height of the tile and the slope of the tile. This is made for artificial slopes.

Ofcourse there is a lot of logic inside two keep the two height representations consistent. However, large terraforming with artificial slopes leeds to inconsistencies, since the grid heightfield is not updated right.

Imho, I would prefer a solution where the grid-heightfield is removed from the code. This need however m****ive patching.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #7 – September 16, 2009, 07:33:04 am

au contraire, i would suggest storing _only_ the four gridpoints, also for slope tools, the tool altering the position of each single point.
gridpoints, in perspective, could be reused one remote day for 3D terrain :

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #8 – September 16, 2009, 07:38:23 am

Quote from: fabio – on September 16, 2009, 07:33:04 am

au contraire, i would suggest storing _only_ the four gridpoints, also for slope tools, the tool altering the position of each single point.
gridpoints, in perspective, could be reused one remote day for 3D terrain :

But then you have to store the height of all 4 corners of a tile to allow artificial slopes. Which at the end is the same as storing the height of the tile and the slope

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #9 – September 16, 2009, 07:52:54 am

yes, all four. but it would give more flexibility, if one day we'll have double height slopes, as well as half slopes. Also in future we could think of grid+texturing and we shouldn't paint/code all the possible new slopes, but only the changes in the grid

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #10 – September 16, 2009, 08:33:27 am

In v102.0, "Restore nature tool" worked for on flat artificial tile and flat artificial hole.
But in current nightly, "Restore nature tool" workes only for 4 slopes.
It means that we don't need to save nature height anymore.
We already know the nature height of slopes.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #11 – October 05, 2009, 07:31:09 pm

Quote from: whoami – on August 24, 2009, 10:40:22 pm

(Not a new bug; tested with Pak64; couldn't find a matching topic)
- find a city building that is built onto a natural slope (using a basement)
- delete this building => basement remains (<-actual bug? separate bug?)
- use tool "restore natural slope" on the tile => natural slope is one level too high

This should be fixed in revision 2700.

However, the restore-natural-slope does not work perfect. The situation has changed since z9999's post, but this tool is still awaiting a fix or a rewrite.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #12 – October 05, 2009, 08:51:45 pm

I think calc_natural_slope should just use the avarage of each of the four adjascent corner to calculate the correct slope.

EDIT: Work in progress: This way could also work; but it gives other problem, when deling many houses. Probably old was better ....

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #13 – October 06, 2009, 05:10:51 am

I did not test your patch, but I also thought about this. My idea was to use the median of the three adjacent corners (rather than the mean value).

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #14 – October 06, 2009, 06:15:28 am

Quote

FIX: restore natural slope when removing buildings on foundations

This make a new bug.

How to reproduce:
1. Build artificial slope on deep sea.
2. Build an attraction on it.
3. Remove the attraction.

Result:
A hole appears onto sea.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #15 – October 07, 2009, 09:48:34 am

Should I make a new bug report topic ?

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #16 – October 07, 2009, 10:14:18 am

Is this a consequence of the bug you posted on the previous page? If not then please describe what you have done. Otherwise, the bug is known

This can easily be fixed. However, there are two different places in the code, where the natural slope is restored: the tool itself and in the building remover code. I would prefer to have only one place that take care of this.

Another related question is: what should happen to player's buildings on artificial slopes? Currently, after removing the building also the natural slope is restored.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #17 – October 07, 2009, 11:21:01 am

Quote from: Dwachs – on October 07, 2009, 10:14:18 am

Currently, after removing the building also the natural slope is restored.

But, very ugly natural slope.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #18 – October 07, 2009, 07:57:36 pm

Perhaps, please check the attached patch. It seems to work in most situations now.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #19 – October 08, 2009, 06:03:15 am

Quote from: prissi – on October 07, 2009, 07:57:36 pm

Perhaps, please check the attached patch. It seems to work in most situations now.

I like this. In many cases, "restores nature slope" tool works as I expected.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #20 – October 08, 2009, 07:18:35 am

There is one bug, see attachment. The same can happen for the reverse situation: tunnel (slope) in the middle then restore the tile above the tunnel, suddenly the ground is below the tunnel.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #21 – October 08, 2009, 01:27:28 pm

Ok, checking for empty ground above/below could be added easily, since it is already there in wkz_set_slope ... Ok, I hope this version geven even more a shape closer to an expected one. Restore will now fail, if at one corner all three edges are of different height, since this can result in some weird slopes.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #22 – October 09, 2009, 06:31:33 pm

It works well. However, I like the real median more: if one has a artificial hill it takes a little bit longer until restoring all tiles will not change anything more. With your original implementation the tool sometimes gives up, even if double slopes are nearby, which are highly unnatural.

Here is a updated patch.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #23 – October 09, 2009, 08:23:37 pm

Nach länerem Rumprobieren finde ich, d****
return (3*128+2 + a+b+c)/3-128;
am besten funktioniert ....

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #24 – October 09, 2009, 08:59:22 pm

Quote from: prissi – on October 09, 2009, 08:23:37 pm

Nach länerem Rumprobieren finde ich, d****
return (3*128+2 + a+b+c)/3-128;
am besten funktioniert ....

Ooops wrong language?

I'll translate that (not because you couldn't, but just so you don't have to bother again, prissi)
EN:
After prolonged testing I think that
return (3*128+2 + a+b+c)/3-128;
works best...

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #25 – October 09, 2009, 09:27:50 pm

Sorry, today I send also Knightly a german pm ... If I switch languages too often, I forget what I was supposed to use.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #26 – October 09, 2009, 09:42:15 pm

I guess we were lucky you did not use japanese

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #27 – October 11, 2009, 12:33:05 pm

Tested in r2733.

This version is very strange again.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #28 – October 12, 2009, 09:02:17 am

Thank you, it looks fine in r2742.
One problem which remained is we can still dig on water.

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #29 – October 12, 2009, 01:30:14 pm

Thank you: Hausbauer was not realizing that this tile is not water and made it ground with water graphic ...

Re: [Bug] r2614: "restore natural slope" results in wrong offset

Reply #30 – October 13, 2009, 06:01:44 am

Thank you problem above was solved in r2748.

But there is a new problem.
When I remove 2 tile building, slope image will remain.