Using their code above, I have made a custom billboard asset maker, the script should be able to auto-render out a billboard asset and texture atlas, though I’m not sure about normals, how would one make a camera render normals?
The three slider values allow you to pinch the top, middle, and bottom width to cut off areas you won’t normally render, like how they pinch the top of it for triangular trees, 1 is full width and 0 is it turns into a single point at the middle.
Basically, the “toRotateCamera” object (name it will try to auto-find is: BillboardCameraArm) is what rotates to take the pictures, and the camera is the camera that should be on the +x axis as a child of that rotator, kindof like an arm with a camera on the end that will spin to take pictures from all angles. The camera should only see the object/s you want to picture though, not everything in the scene, and have a background of transparent colors, with clear flags set to solid color. This was to allow complex objects to be easily baked into billboards, rather than only one mesh allowed, and scene lighting/post-processing is easy to customize.
The only special thing is you need to assign it a material from the nature/speedtree billboard shader thing, under the standard assets of unity, it saves everything in the same location as that material.
Access the wizard under Window / Rendering / Generate Billboard of Object. Huge thanks to SomeGuy22, and the original hard-coded example by NathanJSmith.
using UnityEditor;
using UnityEngine;
//Credits:
//Original hard-coded solution by NathanJSmith: https://answers.unity.com/questions/1538195/unity-lod-billboard-asset-example.html?childToView=1692072#answer-1692072
//Cutomization to script by BarShiftGames on above link, and below link
//Inspiration/Feedback/More coding optimization by SomeGuy22 : https://answers.unity.com/questions/1692296/unable-to-save-generatedrendered-texture2d-to-use.html
#if UNITY_EDITOR
public class GenerateBillboard : ScriptableWizard
{
[Header("")]
[Tooltip("This should be a Nature/Speedtree billboard material")]
public Material m_material;
[Tooltip("How much to pinch the mesh at a certain point, to cut off extra pixels off the mesh that won't be needed.")]
[Range(0, 1)]
public float topWidth = 1;
[Tooltip("How much to pinch the mesh at a certain point, to cut off extra pixels off the mesh that won't be needed.")]
[Range(0, 1)]
public float midWidth = 1;
[Tooltip("How much to pinch the mesh at a certain point, to cut off extra pixels off the mesh that won't be needed.")]
[Range(0, 1)]
public float botWidth = 1;
[Tooltip("Units in height of the object, roughly, this can be fine-tuned later on the final asset")]
public float objectHeight = 0;
[Tooltip("Units in width of the object, roughly, this can be fine-tuned later on the final asset")]
public float objectWidth = 0;
[Tooltip("Usually negative and small, to make it sit in the ground slightly, can be modifed on final asset")]
public float bottomOffset = 0;
[Tooltip("The amount of rows in the texture atlas")]
[Min(1)]
public int atlasRowImageCount = 3;
[Tooltip("The amount of columns in the texture atlas")]
[Min(1)]
public int atlasColumnImageCount = 3;
[Tooltip("The total number of images to bake, ALSO decides how many angles to view from")]
[Min(1)]
public int totalImageCount = 8;
[Header("-")]
[Tooltip("This dictates the rotational center of the render for the billboard, and what is rotated to get different angles.
This also checks once for an object with named "BillboardCameraArm"")]
public GameObject toRotateCamera;
[Tooltip(“This should be child of toRotateCamera, and on the local +x axis from it, facing center with a complete view of the object”)]
public Camera renderCamera;
[Header("Dimensios of atlas")]
public int atlasPixelWidth = 1024;
public int atlasPixelHeight = 1024;
[Header("Optional renderer to set in")]
public BillboardRenderer optionalBillboardRenderer;
private bool doOnce = true;
private bool checkArmOnce = true;
void OnWizardUpdate()
{
string helpString = "";
bool isValid = (m_material != null && objectHeight != 0 && objectWidth != 0 && renderCamera != null && toRotateCamera != null);
if (doOnce)
{
//this will get activated once
doOnce = false;
toRotateCamera = GameObject.Find("BillboardCameraArm");
}
if (toRotateCamera != null && checkArmOnce)
{
//this will check for a camera under toRotateCamera once
checkArmOnce = false;
Camera cam = toRotateCamera.GetComponentInChildren<Camera>();
if (cam != null) { renderCamera = cam; }
}
}
void OnWizardCreate()
{
//function to execute on submit
BillboardAsset billboard = new BillboardAsset();
billboard.material = m_material;
Vector4[] texCoords = new Vector4[totalImageCount];
ushort[] indices = new ushort[12];
Vector2[] vertices = new Vector2[6];
//make texture to save at end
var texture = new Texture2D(atlasPixelWidth, atlasPixelHeight, TextureFormat.ARGB32, false);
//make render texture to copy to texture and assign it to camera
//renderCamera.targetTexture = RenderTexture.GetTemporary(atlasPixelWidth / atlasColumnImageCount, atlasPixelHeight / atlasRowImageCount, 16);
renderCamera.targetTexture = RenderTexture.GetTemporary(atlasPixelWidth, atlasPixelHeight, 16);
var renderTex = renderCamera.targetTexture;
renderCamera.targetTexture = renderTex;
//reset rotation, but camera should be on local +x axis from rotating object
toRotateCamera.transform.eulerAngles = Vector3.zero;
int imageAt = 0;
for (int j = 0; j < atlasRowImageCount; j++)
{
for (int i = 0; i < atlasColumnImageCount; i++)
{
//i is x, j is y
if (imageAt < totalImageCount)
{
//atla them left-right, top-bottom, 0,0 is bottom left
float xRatio = (float)i / atlasColumnImageCount;
float yRatio = (float)(atlasRowImageCount - j - 1) / atlasRowImageCount;
//starts at viewing from +x, and rotates camera clockwise around object, uses amount of vertices set (later down) to tell how many angles to view from
texCoords[imageAt].Set(xRatio, yRatio, 1f / atlasColumnImageCount, 1f / atlasRowImageCount);
imageAt++;
//set rect of where to render texture to
renderCamera.rect = new Rect(xRatio, yRatio, 1f / atlasColumnImageCount, 1f / atlasRowImageCount);
renderCamera.Render();
//read pixels on rec
//Rect rec = new Rect(xRatio * atlasPixelWidth, yRatio * atlasPixelHeight, (float)1 / atlasColumnImageCount * atlasPixelWidth, (float)1 / atlasRowImageCount * atlasPixelHeight);
//texture.ReadPixels(rec, i / atlasColumnImageCount * atlasPixelWidth, (atlasRowImageCount - j - 1) / atlasRowImageCount * atlasPixelHeight);
toRotateCamera.transform.eulerAngles -= Vector3.up * (360 / totalImageCount);
}
}
}
toRotateCamera.transform.eulerAngles = Vector3.zero;
renderCamera.rect = new Rect(0, 0, 1, 1);
RenderTexture pastActive = RenderTexture.active;
RenderTexture.active = renderTex;
texture.ReadPixels(new Rect(0, 0, atlasPixelWidth, atlasPixelHeight), 0, 0);
RenderTexture.active = pastActive;
texture.Apply();
//texCoords[0].Set(0.230981f, 0.33333302f, 0.230981f, -0.33333302f);
//texCoords[1].Set(0.230981f, 0.66666603f, 0.230981f, -0.33333302f);
//texCoords[2].Set(0.33333302f, 0.0f, 0.33333302f, 0.23098099f);
//texCoords[3].Set(0.564314f, 0.23098099f, 0.23098099f, -0.33333302f);
//texCoords[4].Set(0.564314f, 0.564314f, 0.23098099f, -0.33333403f);
//texCoords[5].Set(0.66666603f, 0.0f, 0.33333302f, 0.23098099f);
//texCoords[6].Set(0.89764804f, 0.23098099f, 0.230982f, -0.33333302f);
//texCoords[7].Set(0.89764804f, 0.564314f, 0.230982f, -0.33333403f);
//make basic box out of four trinagles, to be able to pinch the top/bottom/middle to cut extra transparent pixels
//still not sure how this works but it connects vertices to make the mesh
indices[0] = 4;
indices[1] = 3;
indices[2] = 0;
indices[3] = 1;
indices[4] = 4;
indices[5] = 0;
indices[6] = 5;
indices[7] = 4;
indices[8] = 1;
indices[9] = 2;
indices[10] = 5;
indices[11] = 1;
//set vertices positions on mesh
vertices[0].Set(-botWidth / 2 + 0.5f, 0);
vertices[1].Set(-midWidth / 2 + 0.5f, 0.5f);
vertices[2].Set(-topWidth / 2 + 0.5f, 1);
vertices[3].Set(botWidth / 2 + 0.5f, 0);
vertices[4].Set(midWidth / 2 + 0.5f, 0.5f);
vertices[5].Set(topWidth / 2 + 0.5f, 1);
//assign data
billboard.SetImageTexCoords(texCoords);
billboard.SetIndices(indices);
billboard.SetVertices(vertices);
billboard.width = objectWidth;
billboard.height = objectHeight;
billboard.bottom = bottomOffset;
//save assets
string path;
int nameLength = AssetDatabase.GetAssetPath(m_material).Length;
//take out ".mat" prefix
path = AssetDatabase.GetAssetPath(m_material).Substring(0, nameLength - 4) + ".asset";
AssetDatabase.CreateAsset(billboard, path);
path = AssetDatabase.GetAssetPath(m_material).Substring(0, nameLength - 4) + ".png";
byte[] byteArray = texture.EncodeToPNG();
System.IO.File.WriteAllBytes(path, byteArray);
Debug.Log("BILLBOARD ASSET COMPLETED: File saved to " + path + ",
if pressing save in editor breaks billboard, manually assign texture to material");
if (optionalBillboardRenderer != null)
{
optionalBillboardRenderer.billboard = billboard;
}
//cleanup / qol things
RenderTexture.ReleaseTemporary(renderTex);
renderCamera.targetTexture = null;
m_material.SetTexture("_MainTex", texture);
AssetDatabase.Refresh();
}
[MenuItem("Window/Rendering/Generate Billboard of Object")]
static void MakeBillboard()
{
ScriptableWizard.DisplayWizard<GenerateBillboard>(
"Make Billboard from object", "Create");
}
}
#endif
