I have been trying to change the format from a camera that give a texture in Alpha8 to RGBA and have been unsuccessful so far.
This is the code I've tried:
public static class TextureHelperClass
{
public static Texture2D ChangeFormat(this Texture2D oldTexture, TextureFormat newFormat)
{
//Create new empty Texture
Texture2D newTex = new Texture2D(2, 2, newFormat, false);
//Copy old texture pixels into new one
newTex.SetPixels(oldTexture.GetPixels());
//Apply
newTex.Apply();
return newTex;
}
}
And I'm calling the code like this:
Texture imgTexture = Aplpha8Texture.ChangeFormat(TextureFormat.RGBA32);
But the image gets corrupted and isn't visible.
Does anyone know how to change this Alpha8 to RGBA so I can process it like any other image in OpenCV?
A friend provided me with the answer:
Color[] cs =oldTexture.GetPixels();
for(int i = 0; i < cs.Length; i++){//we want to set the r g b values to a
cs[i].r = cs[i].a;
cs[i].g = cs[i].a;
cs[i].b = cs[i].a;
cs[i].a = 1.0f;
}
//set the pixels in the new texture
newTex.SetPixels(cs);
//Apply
newTex.Apply();
This will take alot of resources but it will work for sure.
If you know a better way to make this change please add an answer to this thread.
Related
I just want to be able to see some text rendered in the world.
The only example code that I've found is this:
GameObject Text = new GameObject();
TextMesh textMesh = Text.AddComponent<TextMesh>();
textMesh.font = new Font();
mat.SetColor("_Color", Color.black);
mat.SetPass(0);
meshRenderer.material = mat;
textMesh.text = "Hello World!";
Where mat is defined by the code:
Shader shader = Shader.Find("Hidden/Internal-Colored");
mat = new Material(shader);
mat.hideFlags = HideFlags.HideAndDontSave;
mat.SetInt("_Cull", (int)UnityEngine.Rendering.CullMode.Off);
mat.SetInt("_ZWrite", 0);
mat.SetColor("_Color", Color.blue);
mat.SetPass(0);
This code is added to the Start of MonoBevaviour. And the script is tied to Game Main camera.
No text appears anywhere that I can see.
Ah I think I might have something.
I am not sure though if this works for VR devices - I know that Unity e.g. doesn't render Screenspace overlay canvas on XR.
But back to the point: There is a legacy UI system which is usually not used anymore except for in editor Inspector scripting IMGUI
I think it might actually fit your very special need using GUILayout.Label you should be able to draw a flat label onto the screen even in VR.
With GUI.Label you have full control over the pixel coordinates and size.
public class YourTextDrawer : MonoBehaviour
{
void OnGUI()
{
var color = GUI.color;
GUI.color = Color.green;
var textPosition = new Rect(Screen.width / 2 - 150, Screen.height / 2 - 100, 300, 200);
GUI.Label(textPosition, "Hello World!");
GUI.color = color;
}
}
Not tested, just scrabbling this down from memory right now
And actually thinking about it, this might even work for your image as well
I'm developing a VR App by using skybox Panoramic material. And I want to bind the material with a Texture2D created in C# script, then rendering the Texture2D in native plugin, the codes is below, but the skybox doesn't show anything, why?
private int texWidth = 2304;
private int texHeight = 2304;
private Texture2D tex;
// Start is called before the first frame update
void Start()
{
// Create a texture
Texture2D tex = new Texture2D(2304, 2304, TextureFormat.ARGB32, true);
// Set point filtering just so we can see the pixels clearly
tex.filterMode = FilterMode.Trilinear;
// Call Apply() so it‘s actually uploaded to the GPU
tex.Apply();
init(tex.GetNativeTexturePtr());
// Set texture onto our material
//RenderSettings.skybox.SetTexture("_MainTex", tex);
RenderSettings.skybox.mainTexture = tex;
}
I stumbled upon a strange problem in vuforia.When i request a camera image using CameraDevice.GetCameraImage(mypixelformat), the image returned is both flipped sideways and rotated 180 deg. Because of this, to obtain a normal image i have to first rotate the image and then flip it sideways.The approach i am using is simply iterating over pixels of the image and modifying them.This approach is very poor performance wise.Below is the code:
Texture2D image;
CameraDevice cameraDevice = Vuforia.CameraDevice.Instance;
Vuforia.Image vufImage = cameraDevice.GetCameraImage(pixelFormat);
image = new Texture2D(vufImage.Width, vufImage.Height);
vufImage.CopyToTexture(image);
Color32[] colors = image.GetPixels32();
System.Array.Reverse(colors, 0, colors.Length); //rotate 180deg
image.SetPixels32(colors); //apply rotation
image = FlipTexture(image); //flip sideways
//***** THE FLIP TEXTURE METHOD *******//
private Texture2D FlipTexture(Texture2D original, bool upSideDown = false)
{
Texture2D flipped = new Texture2D(original.width, original.height);
int width = original.width;
int height = original.height;
for (int col = 0; col < width; col++)
{
for (int row = 0; row < height; row++)
{
if (upSideDown)
{
flipped.SetPixel(row, (width - 1) - col, original.GetPixel(row, col));
}
else
{
flipped.SetPixel((width - 1) - col, row, original.GetPixel(col, row));
}
}
}
flipped.Apply();
return flipped;
}
To improve the performance i want to somehow schedule these pixel operations on the GPU, i have heard that a compute shader can be used, but i have no idea where to start.Can someone please help me write the same operations in a compute shader so that the GPU can handle them, Thankyou!.
The whole compute shader are new for me too, but i took the occasion to research it a little bit for myself too. The following works for flipping a texture vertically (rotating and flipping horizontally should be just a vertical flip).
Someone might have a more elaborate solution for you, but maybe this is enough to get you started.
The Compute shader code:
#pragma kernel CSMain
// Create a RenderTexture with enableRandomWrite flag and set it
// with cs.SetTexture
RWTexture2D<float4> Result;
Texture2D<float4> ImageInput;
float2 flip;
[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
flip = float2(512 , 1024) - id.xy ;
Result[id.xy] = float4(ImageInput[flip].x, ImageInput[flip].y, ImageInput[flip].z, 1.0);
}
and called from any script:
public void FlipImage()
{
int kernelHandle = shader.FindKernel("CSMain");
RenderTexture tex = new RenderTexture(512, 1024, 24);
tex.enableRandomWrite = true;
tex.Create();
shader.SetTexture(kernelHandle, "Result", tex);
shader.SetTexture(kernelHandle, "ImageInput", myTexture);
shader.Dispatch(kernelHandle, 512/8 , 1024 / 8, 1);
RenderTexture.active = tex;
result.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
result.Apply();
}
This takes an input Texture2D, flips it in the shader, applies it to a RenderTexture and to a Texture2D, whatever you need.
Note that the image sizes are hardcoded in my instance and should be replaced by whatever size you need. (for within the shader use shader.SetInt(); )
Surprisingly in Unity, for years the only way to simply scale an actual PNG is to use the very awesome library http://wiki.unity3d.com/index.php/TextureScale
Example below
How do you scale a PNG using Unity5 functions? There must be a way now with new UI and so on.
So, scaling actual pixels (such as in Color[]) or literally a PNG file, perhaps downloaded from the net.
(BTW if you're new to Unity, the Resize call is unrelated. It merely changes the size of an array.)
public WebCamTexture wct;
public void UseFamousLibraryToScale()
{
// take the photo. scale down to 256
// also crop to a central-square
WebCamTexture wct;
int oldW = wct.width; // NOTE example code assumes wider than high
int oldH = wct.height;
Texture2D photo = new Texture2D(oldW, oldH,
TextureFormat.ARGB32, false);
//consider WaitForEndOfFrame() before GetPixels
photo.SetPixels( 0,0,oldW,oldH, wct.GetPixels() );
photo.Apply();
int newH = 256;
int newW = Mathf.FloorToInt(
((float)newH/(float)oldH) * oldW );
// use a famous Unity library to scale
TextureScale.Bilinear(photo, newW,newH);
// crop to central square 256.256
int startAcross = (newW - 256)/2;
Color[] pix = photo.GetPixels(startAcross,0, 256,256);
photo = new Texture2D(256,256, TextureFormat.ARGB32, false);
photo.SetPixels(pix);
photo.Apply();
demoImage.texture = photo;
// consider WriteAllBytes(
// Application.persistentDataPath+"p.png",
// photo.EncodeToPNG()); etc
}
Just BTW it occurs to me I'm probably only talking about scaling down here (as you often have to do to post an image, create something on the fly or whatever.) I guess, there would not often be a need to scale up in size an image; it's pointless quality-wise.
If you're okay with stretch-scaling, actually there's simpler way by using a temporary RenderTexture and Graphics.Blit. If you need it to be Texture2D, swapping RenderTexture.active temporarily and read its pixels to Texture2D should do the trick. For example:
public Texture2D ScaleTexture(Texture src, int width, int height){
RenderTexture rt = RenderTexture.GetTemporary(width, height);
Graphics.Blit(src, rt);
RenderTexture currentActiveRT = RenderTexture.active;
RenderTexture.active = rt;
Texture2D tex = new Texture2D(rt.width,rt.height);
tex.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
tex.Apply();
RenderTexture.ReleaseTemporary(rt);
RenderTexture.active = currentActiveRT;
return tex;
}
I add a cube to unity scene. I want to set this cub's texture by using an image.
I use below code to load image and set texture :
Texture2D text2D = new Texture2D(Screen.width, Screen.height,TextureFormat.RGB24 , false);
text2D.SetPixels(((Texture2D)Resources.Load("image")).GetPixels());
MeshRenderer renderer = cube.GetComponent<MeshRenderer>();
renderer.material.mainTexture = text2D;
I see only a gray cube not the image on the scene.
You can shorten this quite a bit with only:
renderer.material.mainTexture = Resources.Load<Texture2D>("image");
Note that if the image is not found then you get null.
To see changes on the Texture2D, use text2d.Apply();
This is even more easy to do.
Try
public GameObject _cube;
void Start()
{
Renderer rend = _cube.GetComponent<Renderer> ();
rend.material.mainTexture = Resources.Load ("image") as Texture;
}
LoadImage method can also be used to do the job. But here, you have to pass in the image as .bytes format.
Example:
public TextAsset image;
void Start()
{
var texture = new Texture2D(100, 100, TextureFormat.ARGB32, false);
texture.LoadImage(image.bytes);
GetComponent<Renderer>().material.mainTexture = texture;
texture.Apply();
}