Heatmap (as a texture or is it possible to use a shader ?)

Hi all

I am evaluating using unity as part of a project and i would like to visualise where mouseclicks has occured on a 3D geometry as a heatmap texture (color decoded)

Basically i have been searching this forum and read some suggestions and problems in storing data in textures and develop a finite-element look-alike shader but is it still possible to find other solutions ?

One would be to use somthing like google analytics tools or clickheat or similar tools that are meant to visualize clicks on webpages.

I would store the user mouse values using raycasting into a database and then pass it to a php that generates a texture/png which can be downloded using www and then finally append it to the geometry.

A couple of problems.

-I need to map the 3D coordinates on the geometry to a 2D picture (i guess this is..well..UV mapping..but i have no idea on how to do this). Even if i use something like screenCoordinate from the raycasting it wouldn't show the colord decoded texture correct,right ?

-There wont be any color decoding gradient between the hotspots(mouseclicks) on the texture.

Is it possible to pass any values to a shader that color decode vertexes depending on number of mouseclicks? I have been looking at the turorial showing the shader program with the color-decoded normals and how to pass a matrix to the program..but i have no idea on how to actually build such a shader.

Any idea is welcome, i am totally new to shaders!

Thanks!

 

Hi,

Was it a bad description of my question or am i just confused about the possibilities of programming a shader?

So, again, anyone knows how i can affect a part of the geometry by color-decod a group of vertex by passing values to the shader. It doesn't need to be visualised in real time.

Thanks

 

I've also been watching this thread hoping someone had some cool ideas on how to do this. This is similar to something I would like to do, but unfortunately I haven't any idea how to accomplish it through shaders. My approach would be to somehow do it with UV mapping and textures, but I haven't actually tried it yet.

 

bigkahuna,

yepp that would be great to have a shader doing that, but after you mentioned the UV mapping and textures again i was looking into raycasting..and i wasn't aware of that it actually could return the UV coordinates and apply a 2Dtexture onto that position.

http://unity3d.com/support/documentation/ScriptReference/RaycastHit-textureCoord2.html


So i guesss you only need to program the setPixel logics so it becomes more of a brush tool that paints onto the 3Dbody and then develop a shader that has a RGB decoder of the texture color.

Well..instead of using setPixel on a larger texture one might want to use the GD-library or something similar in order to make the drawing off-unity so the drawing not being updated every frame. Then import the texture as a "bumpmap"..kind of...

i will try and make some effect out of it!

thanks