103 lines
6.8 KiB
Markdown
103 lines
6.8 KiB
Markdown
# Modify the Terrain heightmap
|
|
|
|
The example code below tells Unity to use the built-in painting Material to modify the Terrain's heightmap, and render a Brush preview in the Scene view.
|
|
|
|
```
|
|
using UnityEngine;
|
|
using UnityEditor;
|
|
using UnityEditor.TerrainTools;
|
|
|
|
internal class CustomTerrainTool : TerrainPaintTool<CustomTerrainTool>
|
|
{
|
|
private float m_BrushOpacity;
|
|
private float m_BrushSize;
|
|
private float m_BrushRotation;
|
|
|
|
// Name of the Terrain Tool. This appears in the tool UI.
|
|
public override string GetName()
|
|
{
|
|
return "Examples/Custom Terrain Tool";
|
|
}
|
|
|
|
// Description for the Terrain Tool. This appears in the tool UI.
|
|
public override string GetDesc()
|
|
{
|
|
return "This is a custom Terrain Tool that modifies the Terrain heightmap.";
|
|
}
|
|
|
|
public override void OnInspectorGUI(Terrain terrain, IOnInspectorGUI editContext)
|
|
{
|
|
editContext.ShowBrushesGUI(5, BrushGUIEditFlags.Select);
|
|
m_BrushOpacity = EditorGUILayout.Slider("Opacity", m_BrushOpacity, 0, 1);
|
|
m_BrushSize = EditorGUILayout.Slider("Size", m_BrushSize, .001f, 100f);
|
|
m_BrushRotation = EditorGUILayout.Slider("Rotation", m_BrushRotation, 0, 360);
|
|
}
|
|
|
|
// Ease of use function for rendering modified Terrain Texture data into a PaintContext. This is used in both OnRenderBrushPreview and OnPaint.
|
|
private void RenderIntoPaintContext(UnityEngine.TerrainTools.PaintContext paintContext, Texture brushTexture, UnityEngine.TerrainTools.BrushTransform brushXform)
|
|
{
|
|
// Get the built-in painting Material reference
|
|
Material mat = UnityEngine.TerrainTools.TerrainPaintUtility.GetBuiltinPaintMaterial();
|
|
// Bind the current brush texture
|
|
mat.SetTexture("_BrushTex", brushTexture);
|
|
// Bind the tool-specific shader properties
|
|
var opacity = Event.current.control ? -m_BrushOpacity : m_BrushOpacity;
|
|
mat.SetVector("_BrushParams", new Vector4(opacity, 0.0f, 0.0f, 0.0f));
|
|
// Setup the material for reading from/writing into the PaintContext texture data. This is a necessary step to setup the correct shader properties for appropriately transforming UVs and sampling textures within the shader
|
|
UnityEngine.TerrainTools.TerrainPaintUtility.SetupTerrainToolMaterialProperties(paintContext, brushXform, mat);
|
|
// Render into the PaintContext's destinationRenderTexture using the built-in painting Material and the built-in ID for the RaiseLowerHeight shader pass
|
|
Graphics.Blit(paintContext.sourceRenderTexture, paintContext.destinationRenderTexture, mat, (int)UnityEngine.TerrainTools.TerrainPaintUtility.BuiltinPaintMaterialPasses.RaiseLowerHeight);
|
|
}
|
|
|
|
// Render Tool previews in the SceneView
|
|
public override void OnRenderBrushPreview(Terrain terrain, IOnSceneGUI editContext)
|
|
{
|
|
// Dont render preview if this isnt a Repaint
|
|
if (Event.current.type != EventType.Repaint) return;
|
|
|
|
// Only do the rest if user mouse hits valid terrain
|
|
if (!editContext.hitValidTerrain) return;
|
|
|
|
// Get the current BrushTransform under the mouse position relative to the Terrain
|
|
UnityEngine.TerrainTools.BrushTransform brushXform = UnityEngine.TerrainTools.TerrainPaintUtility.CalculateBrushTransform(terrain, editContext.raycastHit.textureCoord, m_BrushSize, m_BrushRotation);
|
|
// Get the PaintContext for the current BrushTransform. This has a sourceRenderTexture from which to read existing Terrain texture data
|
|
UnityEngine.TerrainTools.PaintContext paintContext = UnityEngine.TerrainTools.TerrainPaintUtility.BeginPaintHeightmap(terrain, brushXform.GetBrushXYBounds(), 1);
|
|
// Get the built-in Material for rendering Brush Previews
|
|
Material previewMaterial = TerrainPaintUtilityEditor.GetDefaultBrushPreviewMaterial();
|
|
// Specify which PaintContext RenderTexture to use for the brush preview
|
|
TerrainPaintUtilityEditor.BrushPreview previewTexture = TerrainPaintUtilityEditor.BrushPreview.SourceRenderTexture;
|
|
// Render the brush preview for the sourceRenderTexture. This will show up as a projected brush mesh rendered on top of the Terrain
|
|
TerrainPaintUtilityEditor.DrawBrushPreview(paintContext, previewTexture, editContext.brushTexture, brushXform, previewMaterial, 0);
|
|
// Render changes into the PaintContext destinationRenderTexture
|
|
RenderIntoPaintContext(paintContext, editContext.brushTexture, brushXform);
|
|
// Restore old render target. This is necessary because... TODO
|
|
RenderTexture.active = paintContext.oldRenderTexture;
|
|
// Bind the sourceRenderTexture to the preview Material. This is used to compute deltas in height
|
|
previewMaterial.SetTexture("_HeightmapOrig", paintContext.sourceRenderTexture);
|
|
// Specify now that the destinationRenderTexture is going to be used for the next brush preview rendering
|
|
previewTexture = TerrainPaintUtilityEditor.BrushPreview.DestinationRenderTexture;
|
|
// Render a procedural mesh displaying the delta/displacement in height from the source Terrain texture data. When modifying Terrain height, this shows how much the next paint operation will alter the Terrain height
|
|
TerrainPaintUtilityEditor.DrawBrushPreview(paintContext, previewTexture, editContext.brushTexture, brushXform, previewMaterial, 1);
|
|
// Cleanup resources
|
|
UnityEngine.TerrainTools.TerrainPaintUtility.ReleaseContextResources(paintContext);
|
|
}
|
|
|
|
// Perform painting operations that modify the Terrain texture data
|
|
public override bool OnPaint(Terrain terrain, IOnPaint editContext)
|
|
{
|
|
// Get the current BrushTransform under the mouse position relative to the Terrain
|
|
UnityEngine.TerrainTools.BrushTransform brushXform = UnityEngine.TerrainTools.TerrainPaintUtility.CalculateBrushTransform(terrain, editContext.uv, m_BrushSize, m_BrushRotation);
|
|
// Get the PaintContext for the current BrushTransform. This has a sourceRenderTexture from which to read existing Terrain texture data
|
|
// and a destinationRenderTexture into which to write new Terrain texture data
|
|
UnityEngine.TerrainTools.PaintContext paintContext = UnityEngine.TerrainTools.TerrainPaintUtility.BeginPaintHeightmap(terrain, brushXform.GetBrushXYBounds());
|
|
// Call the common rendering function used by OnRenderBrushPreview and OnPaint
|
|
RenderIntoPaintContext(paintContext, editContext.brushTexture, brushXform);
|
|
// Commit the modified PaintContext with a provided string for tracking Undo operations. This function handles Undo and resource cleanup for you
|
|
UnityEngine.TerrainTools.TerrainPaintUtility.EndPaintHeightmap(paintContext, "Terrain Paint - Raise or Lower Height");
|
|
|
|
// Return whether or not Trees and Details should be hidden while painting with this Terrain Tool
|
|
return true;
|
|
}
|
|
}
|
|
```
|