Krzysztof Rećko (chrisr)
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Feb 8 2015, 11:47 AM (136 w, 6 d)

Recent Activity

Mar 11 2017

Krzysztof Rećko (chrisr) added a task to D2556: Fix T50887: Holes in fluid mesh: T50887: fluid simulation: generate mesh bug.
Mar 11 2017, 4:58 PM
Krzysztof Rećko (chrisr) added a revision to T50887: fluid simulation: generate mesh bug: D2556: Fix T50887: Holes in fluid mesh.
Mar 11 2017, 4:58 PM · Physics, BF Blender
Krzysztof Rećko (chrisr) retitled D2556: Fix T50887: Holes in fluid mesh from to Fix T50887: Holes in fluid mesh.
Mar 11 2017, 4:58 PM
Krzysztof Rećko (chrisr) claimed T50887: fluid simulation: generate mesh bug.
Mar 11 2017, 3:57 AM · Physics, BF Blender
Krzysztof Rećko (chrisr) added a comment to T50887: fluid simulation: generate mesh bug.

OK. So. Managed to reproduce this. Does appear to be connected to Fluid boundary -> Surface -> Smoothing option, but only appears at higher resolutions which makes it a pain to debug.

Mar 11 2017, 3:56 AM · Physics, BF Blender

Mar 9 2017

Krzysztof Rećko (chrisr) added a comment to T50887: fluid simulation: generate mesh bug.

Could this be an effect of "Remove air bubbles" option (under "Fluid boundary")?

Mar 9 2017, 10:26 AM · Physics, BF Blender

Apr 15 2015

Krzysztof Rećko (chrisr) added a comment to T43694: Hair Clumps Point to Scene Center When Density is Texture-Controlled.

@Chad Gleason (fahr), the patch wasn't included in official 2.74 release (committed only 6 days before release...), but it is in the newest build from buildbot (https://builder.blender.org/download/) and everything should work fine there :)

Apr 15 2015, 9:45 AM · BF Blender

Apr 7 2015

Krzysztof Rećko (chrisr) resigned from D1207: Fix T43696: Baking tearing normals (Both cycles and BI).
Apr 7 2015, 4:18 AM · BF Blender

Apr 3 2015

Krzysztof Rećko (chrisr) added a comment to D1207: Fix T43696: Baking tearing normals (Both cycles and BI).

@Sergey Sharybin (sergey),

  • Yes, it does help, and probably was done like this at some point (typecasting to double all over the place), but from the point of numerical stability, this is much better anyway - I don't know how extreme would the conditions have to be, but I can imagine the problem showing up with doubles too (it's like postponing the issue until there is more powerful hardware to do very large bakes). We can change to double anyway if you think so but I bet it's not necessary...
  • This function for some reason is used to compute barycentric UV for each triangle on the bake. In case of long triangles, and high resolution of the bake - the errors add up and UVs are not distributed uniformly, hence the tearing (see the bug).
Apr 3 2015, 11:56 AM · BF Blender

Apr 1 2015

Krzysztof Rećko (chrisr) raised the priority of T44222: Crash Rendering (Cycles/Cuda) from "Incomplete" to "Confirmed".

Hey, I can confirm this bug.

  • I have Win7 64, SP1, Nvidia GTX 560Ti, driver 347.88 (17 March).
  • Latest buildbot, and my own build from latest master both have this.
  • Check!
  • Check!
  • Check!
  • Check!
  • Check!
  • Check!
  • Check!
  • Check!
Apr 1 2015, 10:33 PM · BF Blender
Krzysztof Rećko (chrisr) claimed T44185: Hair density influence bug bug.
Apr 1 2015, 7:27 PM · BF Blender
Krzysztof Rećko (chrisr) retitled D1213: Fix T44185: Hair density influence bug from to Fix T44185: Hair density influence bug.
Apr 1 2015, 7:25 PM · BF Blender
Krzysztof Rećko (chrisr) added a revision to T44185: Hair density influence bug bug: D1213: Fix T44185: Hair density influence bug.
Apr 1 2015, 7:25 PM · BF Blender

Mar 31 2015

Krzysztof Rećko (chrisr) added a comment to T44185: Hair density influence bug bug.

@Thomas Beck (plasmasolutions) - Yeah, I opened this exact file, and also made my own test (make hair particle system, assign a texture to density, even without custom material). It was strange because when I made my own test, it also didn't happen a few times, and now it happens always. Maybe there are even more specific conditions?

Mar 31 2015, 1:26 PM · BF Blender
Krzysztof Rećko (chrisr) updated subscribers of T44185: Hair density influence bug bug.

@Thomas Beck (plasmasolutions), that's weird... I have this bug with the latest build. Win7 64. Do you have a different platform? Also, the conditions are pretty specific. This doesn't occur with child particles enabled for example. And when setting density influence to sth different than 1.0, occurs only after second on/off switch.

Mar 31 2015, 1:08 PM · BF Blender

Mar 29 2015

Krzysztof Rećko (chrisr) updated subscribers of T43696: Baking tearing normals (Both cycles and BI).

Hey guys, @marc dion (marcclintdion) was partly right (it's about floating point precision). Took a while to find and fix it though... I hope I've done it right (D1207) :) Any idea who could do review??

Mar 29 2015, 12:32 AM · Rendering, BF Blender
Krzysztof Rećko (chrisr) retitled D1207: Fix T43696: Baking tearing normals (Both cycles and BI) from to Fix T43696: Baking tearing normals (Both cycles and BI).
Mar 29 2015, 12:18 AM · BF Blender

Mar 25 2015

Krzysztof Rećko (chrisr) closed D1177: Fix T43694 - "Hair Clumps Point to Scene Center When Density is Texture-Controlled".
Mar 25 2015, 6:40 PM

Mar 12 2015

Krzysztof Rećko (chrisr) updated D1177: Fix T43694 - "Hair Clumps Point to Scene Center When Density is Texture-Controlled".
Mar 12 2015, 8:30 PM
Krzysztof Rećko (chrisr) retitled D1177: Fix T43694 - "Hair Clumps Point to Scene Center When Density is Texture-Controlled" from to Fix T43694 - "Hair Clumps Point to Scene Center When Density is Texture-Controlled".
Mar 12 2015, 8:29 PM

Mar 6 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

OK, quick update of what I was doing the last couple of days:

Mar 6 2015, 3:49 PM · BF Blender

Mar 2 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

Hey Jiri!

  • The idea behind find_first_points() was to evaluate the function only at "lattice points" to cache them in the hash table. The function evaluation (bvh traversal and actual densfunc()) take 95% of the time in polygonization, so any gain made in this area contributes a lot to speed. But, to be honest, I just coded it this way out of laziness temporarily :-) I could make a version with 26 directions and check how it behaves. If all values will be cached, the speed shouldn't be much worse, and surface accuracy is number 1 priority after all.
  • I don't exactly know what you mean by caching the surface? Updating only the part of the surface that was influenced by a moving metaball or something else? This could be a serious improvement, but not in the case when all metaballs are moving (eg. a fluid simulation). Could you explain it more?
  • Sorry, but I don't have the energy to look at these papers right now (very tiring day at uni, a lot of science done :-)). They look very interesting at first glance. Will check them out in detail later.
Mar 2 2015, 7:54 PM · BF Blender

Feb 26 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

Eh, of course screwed up the last version (bug in makecubetable, I didn't copy everything properly). Here is fixed diff:

.

Feb 26 2015, 9:02 PM · BF Blender
Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

Yes. This should work fine:

.
No functional changes made.

Feb 26 2015, 1:41 PM · BF Blender

Feb 25 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

Hey, made some improvements to converge(). Basically went back to blend of bisection method and linear interpolation from original algorithm. Metaballs should look good now at every threshold and stiffness. Removed the threshold cap. Still, this would need some tweaks to be optimal but it's very hard to test every combination of threshold, stiffness and size.

Feb 25 2015, 11:06 PM · BF Blender

Feb 19 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

OK. Here is the patch with normals from meta:

Feb 19 2015, 9:36 PM · BF Blender

Feb 16 2015

Krzysztof Rećko (chrisr) added a comment to T43678: Metaball optimization.

Cool! Sorry for reordering stuff. As for the normals - I've actually made a quick comparison, have a look:


This is some "benchmark" fluid sim I made for timing the algorithm - 5000 particles towards the end of simulation. "Avg. time" is the average time in milliseconds of 250 frames, only bvh build + tessellation, measured using PIL_check_seconds_timer() on my machine. As can be seen, there definetly is a speed increase (of around 30%) when using angle-weighted accumulation. However, as you said, the surface looks less smooth - this is evident especially on the ball in the middle-lower picture, on which there are some strange features. I think the cause of this is that sometimes during tesselation very thin/small polygons are made, which mess things up. Ways I could think of to make it right:

  • stick with one of the ways to calculate normals or think of even a better one (area-weighted? non-weighted?)
  • make a "fast normal" switch in the mataball panel
  • run the resulting surface through something like "edge collapse" modifier, which would get rid of thin polygons and maybe make the surface look a little bit better

Maybe I'll try checking out the third option (in a few days), to see what the speed impact of this would be. Definitely looking forward to hearing from you!

Feb 16 2015, 3:22 PM · BF Blender

Feb 15 2015

Krzysztof Rećko (chrisr) created T43678: Metaball optimization.
Feb 15 2015, 10:54 PM · BF Blender