1) change shader system: look into fx files
2) tone mapping
   bloom (gaussian blur)
   use downsampling: first 4x4 to luminance then 3 times further to 1x1
   use 3 new render render targets for this

3) mrt channels:

2 mrts:

mrt 1: rgba color + emmissive / luminance
mrt 2: world pos + projected depth
mrt 3: normals + w coordinate
mrt 4: flip-flop for mrt1


4) idea: donwsample color texture for ao

5) use depth formula on projected depth (or use linear depth)
   in order to combine ao + diffuse lookup into on texture lookup


reorder mrts:

mrt 1: rgba color + projected depth
mrt 2: luminance
mrt 3: normals + w coordinate
mrt 4: flip-flop with mrt1 / store luminance after ssao


6) render sun disc



ssao:

1) implement bilateral filtering
2) check physical properties 

paper of 2007 arikan formula:

SW(P, C, r) = 2 * pi * (1 - cos(asin (r / |PC|)))

but not working properly!

3) normal mapping

working but already done!


problems:

4) update of converged regions

something could become visible 

a) from outside
b) from previously occluded regions

a) could use ratio of samples outside current frame / last frame
   but slows donw code

5) dynamic objects:

a) make ao stick on object: this should
   be possible somehow, as the information is still available!!
 
   tried to use difference of ao intensity between previous and
   current frame to find out if pixel ao is not valid anymore.
   but problems as some flickering was introduced while update of 
   dynamic objects was not fast enough (annoying grey fade effect)

b) fix the contact shadow on the floor:

check when pixel not valid anymore: do that by checking for each
sample if they were invalidated recently. if so, then invalidate
current pixel ao. for each point, theoretically you don't have
to compare the depth of the current pixel, but the depth of the
samples taken for ao


idea for incorporation of dynamic objects:

store object id with render target
for each object we know the trafo
when doing the back projection =>

as usual:
we have the world space position of the current pixel
find pixel from last frame using the old projection view trafo

but now we first apply the inverse transformation that brought the
last pixel to the current pixel and then the old projection view!!

=> now we do the equality comparison as usual


for reducing flickering:


keep chain of kernels constant based on the state of convergence=>

only use a single kernel, rotate based on noise texture
we use fixed offset into the noise texture based on the #frames samples were accumulated

problem: 



=========================

1) ssao filter kernel: grows smaller too fast => flickering ... use
adaptive number of samples instead of size?
2) fix color bleeding
3) fix ssao2 so that ssao contribution stays constant for both methods
4) find physical expressions for constants in ssao
5) retry normal discontinuity for ssao filter
6) fix adaptive sampling for ssao and ssao2
   a) sample adaptive if found invalid sample
   b) sample adaptive if number of valid samples small?
   
   q: is it good to choose new weight as we do? (approx 4 frames)
   or shouldn't we just completely reset sample?



shading todo:

bloom
dof
lense flar
god rays
sun disc
environment lighting

1) antialiasing very slow: try separable filter and one direction at a time
2) try cross filter for ssao without tempcoh
3) fix model directory => clean up structure (city/model => models ?)
4) fix namespaces: one main namespace for core functions + math functions?
   one util namespace

5) clean up hacks: 

normalmapping
render target flipflopping for tone mapping
scenequery

fix walk speed for deferred shading

fix color bleeding fix ao2 fix full resolution mode

for the paper: make ao more efficient, for example we do not need to
downsample normal texture for ao version 1 also for full resolution
mode: test what happens if we do not use downsampling, look why
currently so slow with full resolution (was previously > 80 frame or
so!!)


///////////////


always update tempcoh after changes to sample intensity usw.
make halton sequence local to sampling method, no global static!!


make better DOF

clouds

god rays 

animation


################################
## pompeii todo:

1) improve performance:
make better objects (jiri?)

2) use better bvh code (also use size to handle floor plane)

3) shading problems: 

create own normals:

flat normals
use crease angles

find out about degenerate vertices

find out about missing texcoords


#####################################

fix shadows

find out ssao artifacts on edges (near edge no ambient occlusion)


///////////

shadows not working proberly with chc!!! (too many triangles, slow!!)

sibenik: textures dissappear!!

optimize!!
full resolution, sky test (stencil??), shadows
smaller textures??
test normal ssao with simpler shader!

fix normals!!


ssao should be only for ambient lighting
use better buddha model
show rotating spheres
images of sibenik
performance test from vienna?
try out method described in the paper for detecting pixels
unifiy index and counter
fix shadows!
make images with / without filter
use nicer buddha

make samplingstrategy different: poisson has same status as halton,
use one of both (parent class randomsampler)