RenderTexture Painting Examples
Hi all,

I'm far away from my pc, spending time with family over the holidays, but I've prepared a little post for you :)

Here are some examples of things you can do with the RenderTexture painting tip I posted a while ago.

Here is the code again, just to be sure!

Shader code for paintable surface: PasteBin Link 

Paintbrush code  : PasteBin Link

Persistent Damage

Leave persistent damage from laser or other weapons on the environment


This is the basic setup from linked code, Raycast to the mouse position when you click, adding the brush texture to the lightmap based RenderTexture result on collision 


Let the player leave trails with depth in snow/ sand


Set up your shader for tesselation, the Unity Manual here shows how to 

Add a vertex function for displacement, using the Paintmap as a texture reference for pushing the vertices

void disp(inout appdata v)
float d = tex2Dlod(_PaintMap, float4(v.texcoord1.xy, 0, 0)).r * _Height; += v.normal *d;

Now the untouched parts of the snow/sand are slightly higher, and the paintbrush script will push it down

Map Notes

Letting the Player add notes or draw on a map


You dont need the shader for this
Set up a canvas with a raw image, and make a RenderTexture for it

Instead of Raycasting, use the mouse position to paint to the RenderTexture. Get the X and Y coordinates by 

xCoordinate = Mathf.Floor(Input.mousePosition.x - rawImage.rectTransform.position.x);

yCoordinate = Mathf.Floor(Input.mousePosition.y - rawImage.rectTransform.position.y);

DrawTexture(texture, xCoordinate, yCoordinate);

With this you can draw on the RawImage UI component

Player Made Textures

Use the painted RenderTextures as a Texture2D for models


Start the same way as the draw map example

To convert the rendertexture to a usable texture, Make a new Texture2D and read the active RenderTexture's pixels

 Texture2D toTexture2D(RenderTexture rTex)

sourceTex = new Texture2D(rTex.width, rTex.height, TextureFormat.RGB24, false); = rTex;
sourceTex.ReadPixels(new Rect(0, 0, rTex.width, rTex.height), 0, 0);
sourceTex.Apply(); = null;
return sourceTex;

Then assign the result texture to your renderer, and you've got a user made custom material!

Other thoughts:

Splatoon style ink splatting , like the trail example, only multiple raycasts to handle multiple objects better

Strategy game Fog of War, using a dissolving shader

Hope this little post can be useful/ inspire some of you :D

Tier Benefits
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