Heightmap editor

The problem I've found with trying to do heightmaps with fractal programs is that you cannot really decide what you want that area to look like, and instead have to keep generating, adjusting settings, and such in hope that you'll eventually come across something good... Then you have to go through all the loops needed to import that map for each quad. The purpose of this article is to hopefuly provide some starting point for those who know what they want their worldspace to look like.

A few things before we get started.

• The heightmap editor should only be used in cases where your worldspace will be using up more than a 10x10 cell area. The heightmap editor generates cells for 4 entire quads, and may create much more land, and filesize than is practical for smaller projects, like islands. In the case of smaller worldspaces, the landscape editor is strongly suggested since these extra unused cells can be hard to remove.

• The heightmap editor tends to be one of the most resource demanding aspects of the CS, so may not be something which everyone can use due to their hardware limitations. Generally, you need atleast 2gb of RAM to make the heightmap editor work, and may need 3gb if using Vista. Most causes of crashes from the heightmap editor occur due to the high RAM requirements needed to make it function.

• With the exception of adding new quads, or generating LOD meshes, the Heightmap editor should only be used in the initial stages of any project. This is due not only to the mesh errors that occur at the corners of each quad upon saving, but also due to RAM requirements; smaller files have a less impact. Changes to a worldspace after things have been placed in that world should be done using the landscape editor.

• The initial settings for brush strengths and color settings are just plain useless. For most projects, I would suggest using the color settings I have shown here;

The important part is the height values linked to each of the colors. 4096 is roughly where 0 (default water) height is in the CS.

• As long as you are working within the blue to brown to white range, you should be fine with heights. If you start going into pink, your worldspace may have mountains that are too tall, if you go into the black, most of that terrain will be hidden by the eventual LOD meshes.

• The heights between points of your map are also important. Normally, differences of more than 2000 vertical units between two adjacent points of land (each point is arranged in a grid with distances of 128 between points) will make that area unable to be edited with the landscape editor. Differences greater than 4000 vertical units between adjacent points will make the whole cell error out. Meaning that you can't have very many steep, tall cliffs without careful use of the tools.

• • Before opening up the Heightmap editor, it is suggested that you have defined your worldspace in the CS, and saved as a .esp. Opening the heightmap editor before saving can cause some crash issues.**

Getting started.

The toolbar looks something like this. File:Toolbar.jpg From left to right the buttons are: Save, Undo*, Grid on/off, Color Settings, Box Select, Lasso Select, Level Tool, Raise Tool, Lower Tool, Soften Tool, Noise Tool, Smudge Tool, Preview, Overview on/off, Paint Height, and Eyedropper.

• The undo tool is essentially useless in the heightmap editor since even a very brief usage of any tool creates dozens of individual changes. If you make a mistake, you will either need to work over that area again using other tools, or close the heightmap editor without saving (x in the corner), and start over again from scratch.

Brush Control - Applies to most tools

• Size - Determines the radius of the current brush, and corresponds to the same values as the landscape editor. A distance of 1 will affect the closest point of the landscape grid, a distance of 10 will affect points within 1280 units.

• Intensity - Determines the strength of the tool, or rather how quickly that tool works. For example, a setting of 50 with the Raise Tool will cause the area selected to be raised by 50 units for every 1/10th of a second (give or take (probably determined by processor speed)) that you hold down the button. Because most tools work rather quickly, it is usually best to use settings between 1 and 100 for most applications. It is better to make many small changes than to try and do everything at once.

• Falloff - Similar to how it works within the landscape editor, falloff determines how affected things will be according to the distance away from the center of the tool. Simply put, a high falloff makes it so that the center of the tool has more effect than those areas near the edge, while a low falloff makes it so the edge of the tool is affected almost as much as the center. High for hills, low for plateaus.

Noise Parameters - Applies to noise tool and internal fractal generation.

• Frequency - Determines the distance between features. Low frequency means more distance (smoother hills), high frequency means less distance (sharper hills).

Again, lower settings tend to be better than higher ones, each grid denotes 1 cell. Even a setting of 50 can be more noise than you want, a setting of more than 1000 is almost unusable.

• Aplitude - Determines the height change the tool causes, or when used with fractal generation, determines the height of features. In most cases, this should also be set rather low. A combination of 1-5 amplitude, with higher frequencies can help create very rough terrain, but not too rough to be impassable.

• Base Offset - Used almost completely within the internal fractal generator. Used for determining a minimum height for any feature.

• Seed/New Seed button - Is used to determine the formula that is used by the noise tool and fractal generator. Noise generated with the same seed will have features in the same exact area, new seeds will change how the features are applied. When trying to add roughness to terrain, it is suggested to use a new seed after every pass through an area.

• Additive/Subtractive - Determines the behavior of the Noise tool, or the Fractal Generator. With additive checked, it will only cause changes that increase height. With subtractive checked, it will only cause changes that decrease height. If both are checked, the behavior will be the same as having both unchecked.

• • When used with the fractal generator, having additive or subtractive checked will apply the fractal generation over the existing landscape, creating a positive or negative change. If you have a frequency of 1, an amplitude of 1, a baseoffset of 1000, and have additive checked, the entire landscape within the 4 active quads will be raised by roughly 1000 units.

• Random Seed - Causes the seed to change after every use of the Fractal Generator.

• Persistence - Determines how quickly changes will be added with the noise tool (does not seem to affect other tools). Lower is usually better. Default setting is 50, a setting of 20 or so is suggested for most uses.

• Octaves - Determines the roughness of features. Default setting is 8, 1 will create smooth features, settings above 8 seem to make no difference compared to 8, settings above 30 may cause errors.

• Generate Button - Initializes the Fractal Generator, which will usually result in overwriting your terrain, or changing it in some horrible manner. Should only be used when you don't know what you want your worldspace to look like, or when this is something you want to happen.

Erosion Settings The erosion settings can also be rather useful to use somewhere between when you have most of your landmass setup, and before you start doing those smaller touches to keep things interesting.

Notes

The key to using the heightmap editor is using many small changes to get things how you want instead of trying to do it all at once. The intensity/amplitude for any brush should never be above 100 (other than the Soften Tool which needs to be in the 1000+ range to do anything significant) since the brush works rather quickly. Falloff can be useful for adjusting how steep of a change you want based on the center of the radius to its edge. Smoothing and flattening can be rather useful in certain situations.

With the noise tool, using various brush size, intensity, amplitude, frequency, falloff settings along with additive/subtractive, and various seeds can make this tool rather useful in areas that you want a bit of variation, like coastlines, hills, or with very slight settings, can help avoid having those perfectly flat plains. Using subtractive can also make for some interesting canyon formations.

You can do quite alot with the heightmap editor, you just need to be willing to take the time to learn how to use it. Just because you can do large scale work in the heightmap editor doesn't mean that it should be the sole means of doing all your terrain work. Often, the landscape editor, although working on a smaller scale can be much more effective for finishing up an area. The general workflow for any large worldspace should start in the heightmap editor, but end using the landscape editor to make sure those key places have the right heights and shapes.

After you have gotten your landscape to about where you want it, and are ready to proceed to generating regions or adding items, it is suggested that you convert the .esp to a .esm. Doing so will not only lock your landscape as it is within that .esm, but will also allow resources to be freed up, allowing a lower potential for crashing when placing items, or even texturing. Although this will require merging any changes into that .esm (backup before merging, and keep incremental backups of the .esm and .esps (including the merge order)), it can be incredibly useful in ensuring that major errors do not happen while working, requiring you to start from scratch. You can always convert back to a .esp before releasing your mod.

See Also

• Heightmap_Editing More technical explanation.
• Basic_Landscaping_Tutorial