Last updated: October 12, 2007
List of Problems (newest ones first) 
0044 - Memory leak after doing many edits0043 - Flipping heightfield does not clip against irregular selection mask
0042 - Changing focus to another application while mouse is down may cause crash
0041 - Undoing creation of transformed floating selections leaks memory
0040 - Roads plug-ins fail if Illustrator paths contain redundant anchor points
0039 - Plug-in based tools cannot always determine properties of active document
0038 - Affect Unbrushed Areas Only cannot be used with selection mask and/or work area
0037 - Water level changes when view file loaded
0036 - Pasting non-rectangular heightfield as new document hides selection marquee
0035 - Raytrace to Disk dialog always asks for valid filename
0034 - 16-bit TGA elevation export incorrect
0033 - Program crashes when lightsource altitude matches heightfield elevation
0032 - Resizing heightfield doesn't preserve exact span
0031 - Selection mask view mode incorrect during panning0030 - Can't select heightfield after using Paste as New Document command
0029 - Adobe Illustrator plug-ins don't do anything
0028 - Map view recenters after saving and selmask is reset
0027 - Camera dialog says "world units" instead of the current world scale label
0026 - PowerLine plug-in tool sometimes crashes
0025 - Viewpanes fail to update after cancelling plug-in preview0024 - Direct Terragen file I/O incorrect
0023 - Selection, Grow command fails on non-square HFs
0022 - RIB exports have invalid "Os" opacity lists
0021 - Uncaught exception sometimes occurs when using non-planar UV map
0020 - GPF occurs when clicking empty part of scene or map panel bar
0019 - Some ASC files do not import
0018 - Some grayscale BMP files do not load correctly as heightfields or as selection masks
0017 - Non-indexed grayscale TGA bitmaps do not load
0016 - Right mousebutton nor keyboard modifier events forwarded to brushtool plug-ins
0015 - Leveller doesn't run on international versions of Windows
0014 - Some 32-bit TGA bitmaps do not load, or do not have their alpha channels recognized
0013 - Selected areas cannot be spanned to specified values
0012 - Saving large documents fails on network drives
0011 - 16-bit bitmap export produces artifacts
0010 - Large heightfields show artifacts in solid 3D views
0009 - Documentation topics not navigated to when pressing F1 key
0008 - Double-clicking a Leveller document icon does not open file
0007 - Window resizing very slow when "Show window contents while dragging" enabled
0006 - Mouse trails invisible over map pane
0005 - Resampling to lower resolution produces artifacts
0004 - Parts of heightfield become uneditable after reverting
0003 - Filter, Span... command does not work on flat areas
0002 - Raytracer sometimes stops during depthmap building
0001 - Dual monitor support
0044: Memory leak occurs after doing many edits
Versions affected: 2.6 and 2.5
Once the Undo buffer's memory limit is reached, the oldest edits are retired. However, they are not removed from memory. This is more of a problem in 2.6 as it makes more use of immediately-undoable edits.
Workaround: You can forestall edit retirement by increasing the size of the Undo buffer (Preferences/Advanced/Undo), decreasing the memory individual edits can use, or both.
Status: Fixed in 2.6 build 7404.
0043: Flipping heightfield does not clip against irregular selection mask
Versions affected: 2.5, possibly earlier
Using the Filter, Flip command (horizontal or vertical) will cause heightfield data within the selection mask's bounding box but outside its edges to appear on the document.
Workaround: Use rectangular selections.
Status: Fixed for 2.6.
0042: Changing focus to another application while mouse is down may cause crash
Versions affected: all
While pressing the mouse (or stylus pointer) down during tool usage, pressing Alt-Tab to switch to another application and then returning to Leveller may cause it to crash, depending on which tool is current. Other events, such as mounting disk volumes, scheduling other programs to run at prearranged times, priority alert notifications, etc. may also cause Leveller to lose the input focus.
Status: Fixed for 2.6.
0041: Undoing creation of transformed floating selections leaks memory
Versions affected: 2.5, possibly 2.4
A memory leak occurs if one creates a floating selection whose elevation data is a transfomed version of the document (e.g., when using the "Filter, Scale" command) and then the command is undone. The size of the leak is the size of the floating selection's bounding box, four bytes per pixel.
Status: Fixed for 2.6.
0040: Roads plug-ins fail if Illustrator paths contain redundant anchor points
Versions affected: 2.5
The Roads import plug-in and the Select Roads plug-in fail if the Adobe Illustrator file used as input contains paths that have adjacent overlapping anchor points. These define degenerate (zero-length) path segments that confuse the internal road portion rasterizer.
Workaround: Edit the Illustrator file to remove the redundant anchor points.
Status: Will be fixed for 2.6.
0039: Plug-in based tools cannot always determine properties of active document
Versions affected: 2.5
When multiple documents are open, Leveller will not correctly establish the current heightfield object when the tool calls a function concerning the active document, such as GetHFsize(). Instead, the plug-in tool may confuse another open document for the active document. Brush tool plug-ins will not be affected if they use only the LEV_TOOLBRUSHINFO structure.
The problem is in the Leveller program itself; the affected plug-ins are okay. There is no known way for a plug-in to be rewritten to work around the error.
Workaround: Having only one document open at a time works, or, with the target document active, choosing a different tool and then choosing the desired plug-in tool again may work.
Status: fixed for 2.6.
0038: Affect Unbrushed Areas Only cannot be used with selection mask and/or work area
Versions affected: 2.5
Enabling the "Tools, Affect Unbrushed Areas Only" command to set a brush limit mask and then selecting a subset of the heightfield will cause brush tool edits to destabilize Leveller. The program will then crash during the edit or when the edit completes. The same also happens if a work area is set.
Workaround: A full-sized selmask with no work area will be okay. To mimic the effect of a smaller mask, replace the unselected areas with a small transparency value to minimize off-region errors. The easiest way to do this is to do a "Select All", then use "Set Opacity" to change the transparency to 0.01%, then hold down Shift while selecting the subarea. The mask will be full-sized but only the subarea will have a transparency of 100%.
Status: fixed for 2.6.
0037: Water level changes when view file loaded
Versions affected: 2.5 and earlier
If a water level is set and the view saved, loading the view can make the water level appear to shift. A design flaw has the water level saved in the view file as a relative percentage of the heightfield's span, not as an absolute elevation, so if the span has changed, the water level will shift to maintain its relative location.
Workaround: Establish the heightfield's lowest and highest points first, or set one pixel very low and another pixel very high. This will keep the span constant and prevent water level shifting.
Status: Will be fixed for 2.6.
0036: Pasting non-rectangular heightfield as new document hides selection marquee
Versions affected: 2.5
The "Edit, Paste as New Document" command will, if the clipboard contains an irregularly-shaped selection, forget to update the selection mask's existance flag, causing the views to not display the selection marquee.
Workaround: Select the Rectangular selection tool, and while holding down the Shift key, drag a small area within a region that you know to be inside the selection mask (you can see the mask's area if you turn on the mask display mode for the map view). The existance flag will then reset and the marquee will be displayed.
Status: fixed for 2.6.
0035: Raytrace to Disk dialog always asks for valid filename
Versions affected: 2.5
The dialog forgets to ignore the unchecked HDRI option, and won't proceed unless an HDRI output filename is provided as well.
Workaround: Check HDRI on, and specify a valid filename in the HDRI filename field.
Status: fixed for 2.6.
0034: 16-bit TGA elevation export incorrect
Versions affected: 2.5 build 1929 and earlier
Exporting elevations to 16-bit TGA files causes the most significant bit of each integer elevation value to be confused with the pixel's attribute bit, causing it to be lost.
Workaround: use 24-bit TGA, or 16-bit PNG/BMP formats.
Status: fixed in 2.5 build 1930.
0033: Program crashes when lightsource altitude matches heightfield elevation
Versions affected: 2.5 build 1898
Moving the lightsource so that its position makes it touch the heightfield (not merely over the heightfield but actually touching its surface) makes Leveller freeze or crash, when the current view mode uses dot-product lighting.
The lightsource direction vector cannot be normalized since it is zero length and this causes an uncaught division by zero exception.
Workaround: the lightsource should never normally be positioned right on the heightfield surface. Keeping the lightsource outside the heightfield bounds ensures that it never touches.
Status: fixed in 2.5 build 1928.
0032: Resizing heightfield doesn't preserve exact span
Versions affected: 2.5 build 1898 and earlier
When resizing the heightfield, the "Keep current elevation data" option combined with leaving the "Scale it to match" option unchecked does not explicitly guarantee that the current span will be preserved. While the resulting span difference is small, it can be necessary to manually post-correct in projects where exact precision is required.
Workaround: note the span extents before resizing, and afterwards, use the "Filter, Span" command to force the heightfield to have its original span.
Status: fixed in 2.5 build 1928.
0031: Selection mask view mode incorrect during panning
Versions affected: 2.5 build 1898
The map pane selection mask view (available by clicking its toggle button on the map's settings panel) becomes incorrect after the map pane is horizontally panned and new parts of the document are brought into view. A selmask content reference offset is miscomputed, causing the wrong pixels to be drawn.
The error is cosmetic; the selmask itself is not invalid, it only looks so in that particular mode.
Workaround: after panning, press F5 or choose the "View, Refresh" command to updated the map pane.
Status: fixed in 2.5 build 1928.
0030: Can't select heightfield after using Paste as New Document command
Versions affected: 2.4
After pasting a heightfield as a new document using the "Edit, Paste as New Document" command, only the northwest 64 x 64 area of the heightfield can be selected. Viewing the selmask shows random garbage instead of the selmask pixels. Continued use is likely to crash the program.
The problem occurs because the command forgets to resize the selmask to match the pasted heightfield if the clipboard contains an unmasked HF.
Workaround: paste a masked heightfield, or, after using the command, use the Enlarge Canvas command to add one extra pixel of width, then crop the increase away. This will resize the selmask. One should also clear the Undo buffer so that the previous invalid selmask state cannot be regressed to.
Status: fixed in 2.5 build 57.
0029: Adobe Illustrator plug-ins don't do anything
Versions affected: AI.LTF 1.3
The Adobe Illustrator Import and Selector plug-ins let you choose an Illustrator file, and then don't do anything.
The error occurs because some Bezier path handling library code was changed just after the plug-ins were last tested, and the final build process broke the plug-in.
Status: Fixed in AI.LTF 1.4.
0028: Map view centers after saving and selmask is reset
Versions affected: 2.4 build 1616 and earlier
When saving a document (either with File, Save or File, Save As...) the map (nadir) view centers itself and the current selection mask is removed.
The error occurs because code meant to execute only when opening a document was running during save actions as well.
Status: Fixed in 2.4 build 1617.
0027: Camera dialog says "world units" instead of the current world scale label
Versions affected: 2.4 build 1611 and earlier
When trying to aim the camera at a heightfield location using the current world scale, the measurement units combo box says "world units" instead of "meters" (or whatever the world scale label happens to be).
The dialog was accidentally overlooked when making the feature change to enhance old version 2.3 (and earlier) behavior. The error is purely cosmetic and does not otherwise affect operation.
Status: Fixed in 2.4 build 1611.
0026: PowerLine plug-in tool sometimes crashes
Versions affected: Timestamp prior to February 1/2004.
Creating a ramp formation with the PowerLine tool at a horizontal (i.e., east-west) angle and different endwidths produces a GPF error.
The error occurs because the plug-in miscalculates how many scanlines the formation's resultant polygons require, and then underallocates enough memory for the rasterizer.
Workaround: draw the ramp using a north-south direction and manually rotate it afterwards using the Rotate filter.
Status: Fixed after February 1/2004 (2.4-compatible version only)
0025: Viewpanes fail to update after cancelling plug-in preview
Versions affected: 2.4 build 1608 and earlier
When previewing a plug-in effect and then clicking the plug-in's Cancel button, the document viewpanes fail to update to reflect the state the document had prior to running the plug-in. The document is actually fine, but the viewpanes look as if the plug-in had been run. Sometimes simply moving the mouse over the map pane causes the window to refresh, sometimes not.
Workaround: use the "View, Refresh" command to refresh the active document window manually.
Status: Fixed in 2.4 build 1610.
0024: Direct Terragen file I/O incorrect
Versions affected: 2.3 and earlier
When loading a Terragen heightfield file directly with Leveller using its "File, Open..." command or saving as part of an animation export, the elevation data is not read/written correctly, usually expressed as a vertical scaling error.
The error occurs because of a misinterpretation of the Terragen heightfield file format specifications.
Workaround: use the Terragen import/export plug-in.
Status: Fixed in 2.4.
0023: Selection, Grow command fails on non-square HFs
Versions affected: 2.3 and earlier
If the document heightfield has non-square dimensions, the Selection, Grow command will produce a selection marquee that appears split into three parts: two thin rings and what appears to be the original marquee in between them.
The error occurs because the Grow command computes scanline offsets using the heightfield's breadth instead of its width.
Workaround: crop or enlarge the heightfield so that it is square, or: copy the necessary heightfield region to a square heightfield, perform the Grow command there, transfer the selection mask to a paint program and pad it with black pixels (palette index zero) to match the size of the original heightfield, and then import the selmask into the original document.
Status: Fixed in 2.4.
0022: RIB exports have invalid "Os" opacity lists
Versions affected: 2.3
When including the "Os" opacity list in a RIB export, the renderer reports an error when trying to parse the exported RIB file, or draws the heightfield wrong.
Leveller has the data type for RIB opacity wrong (float instead of color), so it emits only a third of the necessary data.
Status: Fixed in 2.4.
0021: Uncaught exception sometimes occurs when using non-planar UV map
Versions affected: 2.3
Using the "Lathe" or other non-planar UV displacement map sometimes causes an uncaught exception to be thrown, crashing Leveller. The heightfield is high resolution, causing the map's coordinate transformer to compute surface normals using too small a derivative.
Workaround: before using the displacement map, resize the heightfield to lower resolution. This will not provide the right level of detail in the resulting mesh, but at least you can visualize a proxy version.
Status: Fixed for next update.
0020: GPF occurs when clicking empty part of scene or map panel bar
Versions affected: 2.2, early 2.3 betas
If you click in the unused part of a scene's or map's panel bar instead of on one of its buttons, Leveller will crash. The panel's mouseUp event handler references a nonexistant button object in such situations.
Status: Fixed in 2.3.
0019: Some ASC files do not import
Versions affected: ASC plug-in 1.x
The 1.x series ASC plug-in assumed that all ASC files had a particular type of fileheader, and that the XYZ data was in regular grid form.
Status: Fixed in ASC plug-in 2.0.
0018: Some grayscale bitmap files do not load correctly as heightfields or as selection masks
Versions affected: 2.3 and earlier
Some grayscale bitmap files use out-of-order palettes, e.g., pure black is not index zero, pure white is not at index 255, and so on. Since the interpretation of indexed images is to use only their pixel index values when loading heightfields or selection masks, this can make the loaded data differ heavily from what is expected if one assumes that the palette is a normal linear grayscale ramp.
Workaround: Open the bitmap file in a bitmap editor and edit its palette to have linear order, so that a pixel with a value of 5 references the palette color RGB(5,5,5), 10 references RGB(10,10,10), etc. Some programs do this automatically if you classify them as grayscale and simply resave them.
Status: Fixed in 2.3. Check the 'Force palette sorting in grayscale bitmaps' option in the Miscellaneous Application Preferences dialog.
0017: Non-indexed grayscale TGA bitmaps do not load
Versions affected: 2.2 and earlier.
Grayscale TGA bitmaps that omit a palette (TGA type 3) are not supported and hence unloadable.
Workaround: Open the TGA file in a bitmap editor and save it as a palette-based grayscale image.
Status: Fixed in 2.3.
0016: Right mousebutton nor keyboard modifier events forwarded to brushtool plug-ins
Versions affected: 2.0 through 2.2.
Interactive tool plug-ins that register themselves as brushes do not receive input events relating to the right mouse button nor the state of keyboard modifier keys such as Shift and Control.
Workaround: Refactor the plug-in into multiple plug-ins, to provide the functionality normally associated with the unavailable events to the unmodified left mouse button events of other plug-ins.
Status: Fixed in 2.3.
0015: Leveller doesn't run on international versions of Windows
Versions affected: 2.2 and earlier.
Leveller stores some binary registry data as strings, and mistakenly assumes it to be 8-bit when it is actually in Unicode format.
Workaround: If possible, configure Windows to use a Western or European language, and reinstall Leveller.
Status: Fixed in 2.3.
0014: Some 32-bit TGA bitmaps do not load, or do not have their alpha channels recognized
Versions affected: 2.2 and earlier.
Ignoring the alpha channel of compressed 32-bit TGA bitmap files was by design. Programs which generate proper 32-bit TGA files set bit 3 of the file header's image descriptor byte, causing Leveller to treat the file as invalid.
Workaround: If the image is compressed, convert it to uncompressed form. Set the file byte at offset 17 decimal to zero, or to 32 if the image has top-down scanline order, and load it again.
Status: Fixed in 2.3.
0013: Selected areas cannot be spanned to specified values
Versions affected: 2.2 and earlier.
The Filter, Span... command does not span selected areas to the values input into its dialog box. Leveller actually spans the entire heightfield to the desired values, but then clips the results to the selection mask, so the selected area tends to have a span which is smaller than the desired span.
Workaround: Copy the region to a flat heightfield having an elevation within the region's span, do the span operation on that heightfield, and then copy the region back to the original heightfield.
Status: Fixed in 2.3.
0012: Saving large documents fails on network drives
Versions affected: 2.2 and earlier.
Large heightfields are written to disk with too large a data transfer block, causing problems on some Windows NT/2000 systems, particularly when saving to network shares.
Workaround: Save the document to a local disk, and then copy it to the network drive using the shell.
Status: Fixed in 2.3.
0011: 16-bit bitmap export produces artifacts
Versions affected: 2.1 and earlier.
There is an over-quantization error in the 16-bit bitmap export.
Status: Fixed in 2.2 build 770.
0010: Large heightfields show artifacts in solid 3D views
Versions affected: 2.1 and earlier.
The OpenGL near plane is too close to the camera, causing Z-fighting artifacts to appear in solid views of large heightfields.
Status: Fixed in 2.2.
0009: Documentation topics not navigated to when pressing F1 key
Versions affected: 2.1 and earlier; also depends on version of Web browser used.
Pressing F1 in dialog boxes will open the documentation's associated HTML page but may not navigate to the topic's anchor. This occurs due to a change in the Windows ShellExecute API or in Internet Explorer.
Status: Fixed in 2.2. There is an option in Leveller 2.2's preferences to launch a specified browser and pass the URL as an argument to it, instead of passing the URL directly to ShellExecute.
0008: Double-clicking a Leveller document icon does not open file
Versions affected: 2.1 and earlier
Double-clicking a Leveller document (a .TER file) icon in Windows usually displays a "Can't open file" dialog box.
Leveller uses WM_COPYDATA to implement its Data Exchange APIs, but the WM_COPYDATA message processing interferes with DDE, and DDE is used by the Windows shell to open documents.
Workaround: You can improve things by running regedit.exe and removing the following registry key:
HKEY_CLASSES_ROOT\Leveller.Document\shell\open\ddeexec
This will make Leveller properly open shell documents. If Leveller is already running, however, it won't do anything, because the non-DDE open method only works when launching Leveller.
Status: Fixed in 2.2
0007: Window resizing very slow when "Show window contents while dragging" enabled
Versions affected: 2.1 and earlier
Enabling the Windows "Show window contents while dragging" option in the Display control panel applet can cause very slow window resizing in Leveller, because the scene pane is redrawn using the default render style.
Workaround: Disable the "Show window contents while dragging" feature of Windows.
Status: Fixed in 2.2
0006: Mouse trails invisible over map pane
Versions affected: 2.0+
The Windows "Show mouse trails" option commonly used by laptop and other non-CRT display users may not work when the mouse is over the map pane and the brush effect preview or elevation tooltip overlays are enabled. What's happening is that Leveller has to redraw the map pane with every mouse move (to redraw the overlays), and this clears off the trailing cursor images drawn by Windows. The exact behavior you get may depend on your video card and its drivers.
Status: No fix is currently planned.
0005: Resampling to lower resolution produces artifacts
Versions affected: 2.1 and earlier
The Edit, Resize Grid, Custom... command does not resample pixels smoothly in all cases when reducing the heightfield's size (e.g., take the test document and resize it to 400 x 420). The problem appears to be that the bicubic interpolation algorithm in use is meant more for enlarging rather than reducing. The bilinear interpolater also has a downward resampling error.
Status: Fixed in 2.2. Bilinear filtering should be used for downwards resampling.
0004: Parts of heightfield become uneditable after reverting
Versions affected: 2.1 and earlier
If a document is resized, and then the file is reverted, the work area rectangle remains stuck at the size the resized document had. If that document was smaller, the reduced work area rect makes parts of the original heightfield uneditable.
Workaround: Choose Select, None, and then View, Set Work Area, or save the document, close it and reopen it.
Status: Fixed in 2.2.
0003: Filter, Span... command does not work on flat areas
Versions affected: 2.1 and earlier
The Filter, Span... command fails to change the elevation of selected areas that are perfectly flat.
Status: Fixed in 2.2.
0002: Raytracer sometimes stops during depthmap building
Versions affected: 2.1 and earlier
Leveller's raytracer sometimes fails to build depth maps when rendering large heightfields. The problem is not easy to produce but once encountered, it can be reproduced reliably. The cause appears to be a lack of precision in the heightfield ray intersection code.
Status: Fixed in 2.2.
0001: Dual monitor support
Versions affected: ALL
Some dual monitor setups may not support Leveller running on the second monitor (either solely on the second screen or spanning the window across the two screens), because Leveller uses OpenGL.
Status: No fix is currently planned.