Rendering: tiles visible in final render

[Sabine]

This is an example of what happens when I render a tweak of one of CristJRogers glorious .frags http://crist-jroger.deviantart.com/art/Hybrid-Pseudo-Kleinian-pack-for-Fragmentarium-588698188
100 tiles, 1000subframes for the upper one, the lower one has only 100 subframes. Great tiling, I give you that!  
I am really lost here. Has anyone any idea what I am doing wrong? No problems with other (older) examples, so probably a setting in IQClouds/Volumetric light settings/Heightfog? Have this problem both on Scorpion and 3dickulus build.
Maybe it's something 'everyone' knows for ages, but I am still really new to the program.
Any help would be appreciated!

[claude]

I'm guessing the visible differences between tiles are coming from some post processing (buffer shader? not sure) that expects to have a whole image, I think the padding setting in the render dialog is meant to help with this

[Sabine]

Thank you very much, Claude! I will have a closer look at the padding info and the BufferShader. Never had this happen in other renders and it is persistent in both the Fragmentarium builds I have.

[M Benesi]

I had this (tiling of big renders instead of getting the whole render) happen a while back:

  3Dickulus found what I had done (hopefully this didn't propagate to other raytracers!!!)- I had changed a line in the raytracer I was using while experimenting:


line 40 in Fast-Raytracer-with-Textures.frag

needs to be...        coord = (gl_ProjectionMatrix*gl_Vertex).xy;
NOT...                        coord = gl_Vertex.xy;


 

[Sabine]

Thanks a lot, Matt! Have checked the raytracers involved

DE-Kn2cr11.frag
3DKn-1.0.5.frag

but no such faulty lines. The only line I saw looking a bit like the one you mentioned was    

viewCoord = gl_Vertex.xy;

but that's a different variable of course... Oh well

[Crist-JRoger]

sabine62, Hello ) glad to see your Frag renders  
When you use tiles, you need use padding too. The value of padding mostly depends from AO and bloom parameters, so DoF too. If you doing render and leave PC for this time, I recommend use big tile resolution, or render in fullscreen view(then just press PrintScreen)
ps. If you using DoF, 1000 subframes is not enough for high quality  

[Sabine]

Great tips, Sergei, will look into this padding thing, thank you! And 2000 will do for dof?  I thought 1000 was a lot already... 

[Crist-JRoger]

And 2000 will do for dof?  I thought 1000 was a lot already...  

It depends from specular(mostly), reflexions and volumetric light settings, if you will set high value of SpecularExp parameter for metallic effect, you'll got noisy DoF at specular areas. Just play with it in preview before final render )
Here for example not enough subframes http://fav.me/d9cuzdl

1:1

[Sabine]

Yep, seen that on my own as well, thank you for the clarifying image, Sergei, I never thought I could get rid of these unsharp areas!
I will test and investigate

[3dickulus]

CJR and I came up with a (sort of) formula for figuring out how much padding is needed...
I'll see if I can find it or remember it and will post it here too, a bit later (unless someone else does first)

edit: actually not how much padding but how much to increase BloomTaps for some consistency between GUI View and Final Image

 -= The test =-
tile size 768x432 padding 100% subframes 32
fragment BloomTest_Files.zip
image http://www.fractalforums.com/images-showcase-(rate-my-fractal)/bloom-test-t23544/

-= The Formula =-
Viewing in GUI 512x288, BloomTaps = 20
Rendering final image 3840x2160, BloomTaps = 150

trial and error really, test, test, test.
To get the final image to look the same as or very similar to the GUI view you have to increase BloomTaps for the Hires Tiled render and (in this case) use 100% padding

[Crist-JRoger]

 3dickulus, Yes I remember that ) and I vote for fullscreen non-tiling render on maximal resolution of your GPU 

[3dickulus]

3dickulus, Yes I remember that ) and I vote for fullscreen non-tiling render on maximal resolution of your GPU 

. lol ..so you can fry bacon and eggs on the GPU while you wait for the image? maybe you have the liquid cooler piped into your hot tub?
you can set tile size to something like 2560x1600 and render just 1 tile
but It really needs that little break between tiles to help keep it from having a meltdown    and to keep the desktop in a responsive state.

[3dickulus]

Thanks a lot, Matt! Have checked the raytracers involved

DE-Kn2cr11.frag
3DKn-1.0.5.frag

but no such faulty lines. The only line I saw looking a bit like the one you mentioned was    

viewCoord = gl_Vertex.xy;

but that's a different variable of course... Oh well

I had this (tiling of big renders instead of getting the whole render) happen a while back:

  3Dickulus found what I had done (hopefully this didn't propagate to other raytracers!!!)- I had changed a line in the raytracer I was using while experimenting:

line 40 in Fast-Raytracer-with-Textures.frag

needs to be...        coord = (gl_ProjectionMatrix*gl_Vertex).xy;
NOT...                        coord = gl_Vertex.xy;
 

@sabine62 try it on viewCoord, observe result, revert back if not successful, I think this bit was in the vertex shader not in the fragment shader iirc

[M Benesi]

  I'm looking at the code now..  viewcoord2 has the projection matrix, so... I dunno if viewcoord needs it.  

  Ok, version 1.19 (3Dickulus) allows me to do a big render.  My mangled version of .25 does not.  I'll recompile from the original .25 code and see if that works.  Update: it does not (for me, compiled from original .25 source).  

comparison between the 2:  .25 allows you to set tile size in the "big render window".  This screws up the tiling (this will be fixed in .26!).  

  For now, revert to a .19 version that works.  Or... also... something about the .19 version, you need to have feedback.frag included or it crashes because of the feedback code.  We have work to do to get this stuff working... older versions (.18 and below???) should work because the didn't have feedback stuff.  sigh... just created some sort of neat feedback frags too....

.19 big render dialogue (click to enbiggen):


.25 big render dialogue (click to enbiggen):

[Crist-JRoger]

. lol ..so you can fry bacon and eggs on the GPU while you wait for the image?

No, GPU usage can't be more than 100 % or less ) it always 100% when you do render in Frag and temperature always the same, and I think you know that ) Nvidia not so hot as ati 

maybe you have the liquid cooler piped into your hot tub?

No

you can set tile size to something like 2560x1600 and render just 1 tile

No, and I wrote about that not so long ago. Window-mode or fullscreen-mode much more stable than tile render, and I wrote about that so long ago 
Just run render and leave PC until the end