A short article explaining some of the basic functions of the road editor tool in Anteworld game in sandbox mode. This is the first part that will be extended later as the improvements to the road tool will be made.
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Roads
Roads in Outerra engine can be created by opening the road tool from sandbox menu. The tool allows you to create new roads or to modify the existing ones. New roads are created by placing way points (ctrl+LMB), both the existing and new roads can be modified by selecting road node and adjusting its attributes or position.
Here are the keys that can be used with the road tool (you can find them in the help tab of the road tool as well):
| m | move the way point on the terrain, copying the terrain contours |
| shift+m | move the way point on the terrain, with the height locked to the original value |
| v | adjust height of the way point |
| q | move to the next way point |
| shift+q | move to the previous way point |
| b | append a new way point |
After the nodes are placed or adjusted, you can press the make road button to physically create the road or to rebuild it with adjusted parameters.
You can also select the road type and markings. The selection is limited at the moment; the road system will support much more road types, profiles and markings when it's finished.
Selected node is show with a node selector, drawn as three concentric circles. The circles show the widths of three important road node dimensions: yellow for road width, orange for border extension of the road, and finally the red showing width of transitional area on the road sides.
While the meaning of the first two should be immediately obvious, the transitional width needs some explanation. It specifies the width of the area across which the height of the road surface transitions into the surrounding terrain. If you are creating roads that are roughly at the same level with the terrain, its effect is not that visible. As soon as the road is elevated above or below the terrain, or the terrain is sloped, the effect of the transitional value shows.
The following pictures show the effect of the transitional width value on how the road is blended with the terrain. Just the single selected node has its transitional value changed:
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| 8m transitional width |
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| 23m transitional width |
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| 1m transitional width |
Tangents
Roads are created from the placed way points using Cubic Hermite splines (for the interested, the algorithm has been briefly described in an earlier blog post). The splines allow for arbitrary selection of tangent (= the direction of the road at given point). Engine supports three ways of computing the tangents:
- By default it's computed to be parallel with the line between two neighboring way points. This is OK in most cases when you are freely drawing the road.
- Fit to match the direction of previous segment
- Fit to match the direction of following segment
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| Tangent computed from two neighbor nodes |
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| Tangent set to match the previous road segment |
Connecting roads
Until there's a tool that will snap roads together, you can only try to join them manually. Here are a few tricks how to do it.
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| Initial state |
Move the last node a bit back (using 'm'), and place additional node at the end of the connecting road. Enlarge the road width to get rid of the sharp connection, and move the node so that there's no gap.
The road you are connecting to is usually slightly sloped, and you need to adjust slant of the road node with which you are connecting, together with the height of the node. The height can be changed either using the elevation± slider, or by entering vertical-move mode using key 'v'.
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| Linear width interpolation |
1 comment:
When I go back to the road the changes are permanent. Is this local only on my computer or am I making changes others can see? Also its not clear how to rotate a spline node. When I place them its always turned 30 degrees left or right.
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