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Fernando Alcala (TriFractal)
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User Since
Jul 8 2020, 8:54 PM (115 w, 5 d)

Recent Activity

Aug 26 2022

Fernando Alcala (TriFractal) updated subscribers of T100629: New caustics system only considers one shader node..

currently a limitation

This is unfortunately a limitation of the current implementation: We assume that there is only 1 bsdf per refractive interface casting shadow caustics, which explains why only the 1st bsdf is taken into account. This may change in the future, since I can imagine how a variant of the setup you have here could be used for dispersion.

Aug 26 2022, 4:25 AM · Render & Cycles, BF Blender

Jun 25 2022

Fernando Alcala (TriFractal) awarded D15286: Cycles: Integration of path guiding using Intel's Open Path Guiding Library (Open PGL) a Love token.
Jun 25 2022, 5:48 AM · Cycles

Jun 11 2022

Fernando Alcala (TriFractal) added a comment to T98780: A black spot in the sun on reflective surface.

Windows 10, GTX 1080Ti

Jun 11 2022, 8:45 PM · Render & Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T98780: A black spot in the sun on reflective surface.

It has to do with Filmic. In 3.2, both Filmic and Filmic Log get the black spot. In 3.1, only Filmic Log gets the black spot.

Jun 11 2022, 7:06 AM · Render & Cycles, BF Blender

Apr 15 2022

Fernando Alcala (TriFractal) added a comment to T97027: Regression: Triangle edges visible (ray/triangle intersection issue?).

related? T97259

Apr 15 2022, 12:50 AM · Render & Cycles, Cycles, BF Blender

Mar 24 2022

Fernando Alcala (TriFractal) added a comment to T96718: Regression: Photo "blowout" when rendering and denoising in 3.1.0.

I can reproduce on Ubuntu 21.10 with a Threadripper 3000.
Cannot reproduce on Windows 10 with an i7 4790k or Threadripper.

Mar 24 2022, 7:48 AM · Render & Cycles, BF Blender

Mar 22 2022

Fernando Alcala (TriFractal) added a comment to T96604: Multiscatter GGX Glass and Principled BSDF shows a seam in rendering that shouldn't be there.

If you move the camera in this report's file, you get the same artifacting. They're just elongated in the cylinder's direction.

Mar 22 2022, 4:55 AM · Render & Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T96604: Multiscatter GGX Glass and Principled BSDF shows a seam in rendering that shouldn't be there.

Camera moving in

Camera rotating

Roughness animated from 0 to 1

Mar 22 2022, 3:39 AM · Render & Cycles, BF Blender

Mar 21 2022

Fernando Alcala (TriFractal) added a comment to T93068: Cycles Transparent Shading BUG with rough Multiscatter GGX.

Camera moves into it

Camera rotates

Roughness is animated from 0 to 1

Roughness is animated from 0 to 0.1

Mar 21 2022, 9:28 PM · Cycles, Render & Cycles, BF Blender

Feb 4 2022

HEYPictures (HEYPictures) awarded T94425: Volume artifacts when transparent interfaces are in front, and issues with Min Light and Transparency Bounces a The World Burns token.
Feb 4 2022, 8:28 PM · Render & Cycles, BF Blender

Feb 3 2022

Fernando Alcala (TriFractal) added a comment to T94425: Volume artifacts when transparent interfaces are in front, and issues with Min Light and Transparency Bounces .

Showing how smoke resolution relates to block size.

Feb 3 2022, 7:27 AM · Render & Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T94394: Volume blocky through glas.

It's because you simulated it at a lower resolution, making the blocks almost fill the hourglass. As I mentioned in the detailed report, this matters.

Feb 3 2022, 7:11 AM · Physics, Nodes & Physics, Render & Cycles, Cycles, BF Blender

Feb 2 2022

Fernando Alcala (TriFractal) added a comment to T94394: Volume blocky through glas.

You should merge this report to T94425, I describe the issue better there. And I can still reproduce on the latest 3.1 beta and 3.2 alpha.

Feb 2 2022, 4:26 AM · Physics, Nodes & Physics, Render & Cycles, Cycles, BF Blender

Dec 28 2021

Fernando Alcala (TriFractal) added a project to T94425: Volume artifacts when transparent interfaces are in front, and issues with Min Light and Transparency Bounces : Render & Cycles.
Dec 28 2021, 12:54 AM · Render & Cycles, BF Blender
Fernando Alcala (TriFractal) created T94425: Volume artifacts when transparent interfaces are in front, and issues with Min Light and Transparency Bounces .
Dec 28 2021, 12:53 AM · Render & Cycles, BF Blender

Dec 26 2021

Fernando Alcala (TriFractal) added a comment to T94394: Volume blocky through glas.

Increase "Min Light Bounces"

Dec 26 2021, 10:18 PM · Physics, Nodes & Physics, Render & Cycles, Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T94394: Volume blocky through glas.

you can upload the file, it's just that we have to do the baking

Dec 26 2021, 6:24 PM · Physics, Nodes & Physics, Render & Cycles, Cycles, BF Blender

Dec 14 2021

Fernando Alcala (TriFractal) added a comment to T93978: increasing pixel size now reduces performance rather than improving it..

1080 Ti, 4790k, 16Gb of RAM
I can go up to 8000 before I run out of ram.
It takes like 40 seconds to change pixel size. Performance seems consistent.

Dec 14 2021, 10:02 PM · Render Pipeline, Render & Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T93978: increasing pixel size now reduces performance rather than improving it..


no issue with a recent build

Dec 14 2021, 7:00 AM · Render Pipeline, Render & Cycles, BF Blender
Fernando Alcala (TriFractal) added a comment to T93964: long pause between moving the mouse and the viewport moving. Once moving remains responsive..

Latest alpha has no issue for me

Dec 14 2021, 4:09 AM · Render & Cycles, Cycles, BF Blender

Nov 22 2021

Fernando Alcala (TriFractal) added a comment to T93068: Cycles Transparent Shading BUG with rough Multiscatter GGX.

Add the Render & Cycles project tag

Nov 22 2021, 8:29 PM · Cycles, Render & Cycles, BF Blender

Nov 13 2021

Fernando Alcala (TriFractal) added a comment to T92450: Cycles Transparent Shading BUG.

You should create another report for the rough one

Nov 13 2021, 8:53 PM · Render & Cycles, BF Blender

Oct 30 2021

Fernando Alcala (TriFractal) awarded T92571: Cycles: path guiding a Love token.
Oct 30 2021, 8:33 PM · Cycles, Render & Cycles

Oct 28 2021

Fernando Alcala (TriFractal) added a comment to T92536: Mantaflow APIC creates wrong droplet behaviour.

While APIC has clear issues, it's Mantaflow that's the problem. T85212

Oct 28 2021, 11:26 PM · Nodes & Physics, BF Blender

Oct 27 2021

Fernando Alcala (TriFractal) added a comment to T85259: Multiscatter GGX artefacts for rough glass.

Here's another MGGX roughness related bug T92520

Oct 27 2021, 9:03 AM · Render & Cycles, BF Blender

Sep 8 2021

Fernando Alcala (TriFractal) added a project to T88418: Duplicating a passive body can make the child meshes not update: BF Blender.
Sep 8 2021, 7:03 PM · BF Blender, Nodes & Physics, Physics

Sep 5 2021

Fernando Alcala (TriFractal) added a comment to T88257: Mantaflow: emit smoke from particles can't inherit velocity..

source 0

source 1

source 2

reason 52 why mantaflow sucks: mantaflow geometry

flipfluids geometry

Sep 5 2021, 10:22 PM · Nodes & Physics, BF Blender

Aug 31 2021

Fernando Alcala (TriFractal) added a comment to T91028: Rigid body Bounciness parameter not functioning.

Actually, never mind.

Aug 31 2021, 5:22 AM · Nodes & Physics, Physics, BF Blender

Aug 30 2021

Fernando Alcala (TriFractal) added a comment to T91028: Rigid body Bounciness parameter not functioning.

Bounciness is just broken.

Aug 30 2021, 8:26 PM · Nodes & Physics, Physics, BF Blender

Jul 30 2021

Fernando Alcala (TriFractal) added a comment to T89463: Rigid body bugs.

Why do the bounces seem to occur at different heights? Not enough temporal resolution since the FPS is too low. Set your FPS to 240 or higher. At frame 9→10, the ball travels 14.5cm. Between frame 10 and 11, Bullet substeps 50 times which allows the ball to correctly bounce. Set the substeps to 1 and you will see that the ball "correctly" continues downward, penetrating the floor.

Jul 30 2021, 10:31 PM · Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T89463: Rigid body bugs.

Look at it tip from a single vertex to a square that's 10mm large. Very nice.

Jul 30 2021, 7:52 PM · Nodes & Physics, BF Blender

Jul 29 2021

Fernando Alcala (TriFractal) added a comment to T76356: Very slow performance when copying rigid body physics.

26b2a35dd44c has fixed this.

Jul 29 2021, 10:55 PM · Performance, Dependency Graph, Nodes & Physics, BF Blender

Jul 28 2021

Fernando Alcala (TriFractal) added a comment to T89463: Rigid body bugs.

I can at least commend you for setting object scales to 1. However, using highly detailed geometry and the mesh solver is where you made your mistakes.
For the first file, what is the intent? Do you want a sphere or a highly faceted ball? If you want a sphere, why don't you use the sphere solver? If you want a highly faceted surface then the real issue is that you have a flat ground plane using mesh. Simply change the ground to box, and after 15 seconds, the ball will come to rest. This is entirely accurate since the center of gravity is much higher than the little triangle that its trying to balance on. This is simply user error.

Jul 28 2021, 10:13 PM · Nodes & Physics, BF Blender

Jul 21 2021

Fernando Alcala (TriFractal) added a comment to T90014: RigidBody explodes.

It's not the wall that's broken, but surprisingly the floor. It's like an invisible force field. Sometimes it acts like a solid. Once the bug is interacted with by some rigid body, following rigid bodies are fine. But it can only be moved along the Z-axis. Changing to box collider or removing and apply rigid body does nothing. What a weird bug.

Jul 21 2021, 8:35 PM · Nodes & Physics, BF Blender

Jul 8 2021

Fernando Alcala (TriFractal) added a comment to T89662: Baking partikel sim. after smoke sim. baking -> ultra slow.

I also tested rigid bodies and cloth. It looks like that the playback delay from other bakes is added to whatever you're currently baking. So a new task or title change should be done.
We can see that after I delete the cloth, the smoke sim bakes very quickly.

Remembering the speed of a normal smoke bake, we can see that the rigid body sim also slows down the smoke bake.

Jul 8 2021, 5:40 AM · Physics, BF Blender

Jul 5 2021

Fernando Alcala (TriFractal) added a comment to T89662: Baking partikel sim. after smoke sim. baking -> ultra slow.

Same thing happens even when they're different.

Jul 5 2021, 10:01 PM · Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T89662: Baking partikel sim. after smoke sim. baking -> ultra slow.

I have a smoke sim with domain 256 baked to frame 40. When the particle sim is baking from frame 1-40, it is slow, but after that, as fast as normal. It is 100% dependent on what the fluid sim is.

Jul 5 2021, 7:13 PM · Physics, BF Blender

Jul 2 2021

Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Add quick smoke to default cube. Set vorticity to .1.

Jul 2 2021, 5:39 AM · Physics, Nodes & Physics, BF Blender

Jun 18 2021

Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Most of it is just experimentation. What you'll find in the end are two main issues.

  1. Large timesteps cause strange behaviors in the base simulation.
    • Also affects vorticity and dissolve as if the influence of these isn't divided by the timestep. I don't know if it directly affects fluid particles. Since the simulations are overly energetic at high timesteps, is the increase of particles from the base sim or timestep?
  2. The domain is asymmetric.
Jun 18 2021, 7:44 PM · Physics, Nodes & Physics, BF Blender

Jun 3 2021

Fernando Alcala (TriFractal) awarded D11400: Mantaflow bake optimization a Like token.
Jun 3 2021, 3:23 AM · Nodes & Physics

Jun 2 2021

Fernando Alcala (TriFractal) added a comment to T86319: Rigid body : the animation of the angle constraint parameters does not work with an animated object.

Things I found. Angular Limit cannot be animated, but it does apply only when it goes back to frame 1. Enabled and Breakable can be animated freely. Disable Collisions can be animated freely, but a weird thing can happen in this particular scene. If the "door" doesn't have enough energy to penetrate the cube, they will not intersect when collisions are disabled. Sometimes, weird things will happen like at 1:08. I've also seen the door very slowly penetrate the cube.

Jun 2 2021, 7:44 PM · Animation & Rigging, Dependency Graph, Nodes & Physics, BF Blender

May 29 2021

Fernando Alcala (TriFractal) added a comment to T85529: Rigid body constraint hinge shift with animated object .

I've come across this issue as well. Whenever you're animating a rigid body on frame 1 or before, it bugs out like that. The workaround is to not use frame 1.

May 29 2021, 12:32 AM · Nodes & Physics, BF Blender

May 25 2021

Fernando Alcala (TriFractal) added a comment to T81011: Mantaflow - Flickering Square pattern of the particles.

Domain 768 with particle settings: upres 1, potential and update radius 1

May 25 2021, 10:05 PM · Nodes & Physics, BF Blender

May 23 2021

Fernando Alcala (TriFractal) added a comment to T81011: Mantaflow - Flickering Square pattern of the particles.

Your resolution is too low.
Your setup. Domain 64 with particle settings: upres 1, potential and update radius 1

Domain 64 with default particle settings: upres 1, potential and update radius 2

Domain 64 with particle settings: upres 10, potential and update radius 4

Domain 128 with default particle settings: upres 1, potential and update radius 2

Domain 256 with particle settings: upres 1, potential and update radius 1

May 23 2021, 8:44 AM · Nodes & Physics, BF Blender

May 20 2021

Fernando Alcala (TriFractal) updated the task description for T88418: Duplicating a passive body can make the child meshes not update.
May 20 2021, 4:06 AM · BF Blender, Nodes & Physics, Physics
Fernando Alcala (TriFractal) removed a project from T88418: Duplicating a passive body can make the child meshes not update: BF Blender.
May 20 2021, 3:58 AM · BF Blender, Nodes & Physics, Physics
Fernando Alcala (TriFractal) created T88418: Duplicating a passive body can make the child meshes not update.
May 20 2021, 3:58 AM · BF Blender, Nodes & Physics, Physics

May 14 2021

Fernando Alcala (TriFractal) added a comment to T88257: Mantaflow: emit smoke from particles can't inherit velocity..

Same as T84001

May 14 2021, 7:24 PM · Nodes & Physics, BF Blender

Apr 18 2021

Fernando Alcala (TriFractal) renamed T85212: Mantaflow instability from Increasing timesteps in Mantaflow causes chaotic results to Mantaflow instability.
Apr 18 2021, 9:01 PM · Physics, Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Viscosity testing. For PIC, FLIP ratio is set to 0. For FLIP, FLIP ratio is set to 1.

Apr 18 2021, 8:35 PM · Physics, Nodes & Physics, BF Blender

Apr 10 2021

Fernando Alcala (TriFractal) added a comment to T87085: Bakeing Rigid Body too much slow.

As Philipp said, they changed the "time resolution" setting for rigid bodies. When we set the time settings to the equivalent of pre 2.90 (600steps per second/24fps = 25 steps per frame) we get it to work in real time.

Apr 10 2021, 8:21 PM · Nodes & Physics, BF Blender

Mar 4 2021

Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Forgot to do liquids. APIC. By the way, version: 2.92.0, branch: master, commit date: 2021-02-24 16:25, hash: rB02948a2cab44

Mar 4 2021, 8:28 AM · Physics, Nodes & Physics, BF Blender

Mar 3 2021

Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Create two cubes. The domain is 25cm25cm50cm at 0X 0Y 15cmZ and the cube is 10cm10cm10cm at 0X 0Y 0Z. Everything is default expect for the timestepping.

Mar 3 2021, 8:45 PM · Physics, Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T85212: Mantaflow instability.

Can't believe I didn't think of this. Here are some tests of 2400 fps simulations with no timestepping, the temporal equivalence of 24 fps and 100 timestepping.
Smoke, 64 domain, 2400fps edited to real-time. Looks exactly like 24fps with 100 timestepping:

Mar 3 2021, 8:27 AM · Physics, Nodes & Physics, BF Blender

Feb 26 2021

Fernando Alcala (TriFractal) added a comment to T85932: Compund_Collision_chain demo not working properly .

D5797#237065 comment section?

Feb 26 2021, 7:40 PM · Nodes & Physics, BF Blender

Feb 25 2021

Fernando Alcala (TriFractal) added a comment to T85932: Compund_Collision_chain demo not working properly .

David's original scene Comptest Chain.blend (6mb) used three separate cubes each with a convex hull. This one works.


Then Dalai did some "cleanup" compound_collision_chain.blend (777kb) and merged those cubes, creating a concave shape that still has convex hull. This is what you download off of Blender. Doesn't work.

David then fixes this compound_collision_chain.blend (253kb) by separating the bottom cube and removing the rigid bodies from the wall.

Feb 25 2021, 10:38 PM · Nodes & Physics, BF Blender

Feb 22 2021

Fernando Alcala (TriFractal) closed T84001: Mantaflow Initial velocity not working PROPERLY as Archived.

It's a limitation.

Feb 22 2021, 8:50 AM · Nodes & Physics, BF Blender

Feb 9 2021

Fernando Alcala (TriFractal) added a comment to T84001: Mantaflow Initial velocity not working PROPERLY.

The "issue" that I had was that the size of the simulation was too small for the timestep size. Normal 50 in meter sized sims works fine:

Feb 9 2021, 11:04 PM · Nodes & Physics, BF Blender

Jan 29 2021

Fernando Alcala (TriFractal) added a project to T85212: Mantaflow instability: Nodes & Physics.
Jan 29 2021, 8:44 PM · Physics, Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) created T85212: Mantaflow instability.
Jan 29 2021, 8:44 PM · Physics, Nodes & Physics, BF Blender

Jan 7 2021

Fernando Alcala (TriFractal) added a comment to T82817: Cloth+RigidBody limitation.

I found the issue. Collision sources Final and Deform don't work (as expected) but Base does.

Jan 7 2021, 1:14 AM · Nodes & Physics, BF Blender

Dec 30 2020

Fernando Alcala (TriFractal) added a comment to T84001: Mantaflow Initial velocity not working PROPERLY.

With respect to particles, initial velocity source does change the simulation, but at an imperceptible level compared to using meshes.

Dec 30 2020, 12:10 AM · Nodes & Physics, BF Blender

Dec 28 2020

Fernando Alcala (TriFractal) closed T84130: Strange outcome of liquid simulation as Archived.

It's called narrow band


Dec 28 2020, 6:30 AM · Nodes & Physics, BF Blender

Dec 23 2020

Fernando Alcala (TriFractal) added a comment to T84001: Mantaflow Initial velocity not working PROPERLY.

Here I compare between 0 and 100 (max) for the initial velocity. There's very little difference in using the maximum value.

Dec 23 2020, 6:52 AM · Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T83679: Cloth collision with rigidbody object doesn't work.

version: 2.92.0 Alpha, branch: master, commit date: 2020-12-20 17:48, hash: d283a093d664

Dec 23 2020, 12:39 AM · Nodes & Physics, BF Blender

Dec 17 2020

Fernando Alcala (TriFractal) closed T83798: Clothes colliding with another does not work correctly. as Resolved.
Dec 17 2020, 10:01 AM · Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T83798: Clothes colliding with another does not work correctly..

Turn "Single Sided" off in the collision settings

Dec 17 2020, 12:19 AM · Nodes & Physics, BF Blender

Dec 15 2020

Fernando Alcala (TriFractal) added a comment to T83594: Rigid Body and Cloth simulations are indeterministic and borderline unusable in production.

Blender's rigid body documentation is useless. But when you learn how to use it:

Dec 15 2020, 1:25 AM · BF Blender

Nov 5 2020

Fernando Alcala (TriFractal) added a comment to T82280: Quick Smoke Doesn't Work In Already Established Scene.

I had no issues

Nov 5 2020, 4:28 AM · Nodes & Physics, BF Blender

Oct 27 2020

Fernando Alcala (TriFractal) added a comment to T82126: Unexpected explosion on pieces of a fractured cube (Added Rigid Body).

You are doing something wrong, I ran into no issues.

Oct 27 2020, 7:46 PM · Nodes & Physics, BF Blender

Sep 9 2020

Fernando Alcala (TriFractal) closed T79764: Rigid body primitive capsule is broken as Resolved.

The September 7 dev notes mentioned an update to the Bullet library. I downloaded b351607996e4 and the issue wasn't there. Every primitive can be used now! The last thing to make rigid bodies perfect is resolving the need to enable a collision margin of 0m to fix some interactions, but I can wait for that.

Sep 9 2020, 9:06 AM · Nodes & Physics, BF Blender

Aug 15 2020

Fernando Alcala (TriFractal) updated the task description for T79764: Rigid body primitive capsule is broken.
Aug 15 2020, 2:05 AM · Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) added a comment to T79764: Rigid body primitive capsule is broken.

Should have added that in the instructions, capsules push each other slightly while other primitives don't.

Aug 15 2020, 2:02 AM · Nodes & Physics, BF Blender

Aug 14 2020

Fernando Alcala (TriFractal) added a project to T79764: Rigid body primitive capsule is broken: Nodes & Physics.
Aug 14 2020, 3:41 AM · Nodes & Physics, BF Blender
Fernando Alcala (TriFractal) created T79764: Rigid body primitive capsule is broken.
Aug 14 2020, 3:41 AM · Nodes & Physics, BF Blender

Jul 8 2020

Fernando Alcala (TriFractal) added a comment to T76356: Very slow performance when copying rigid body physics.

2.83
I too have encountered this problem.
Some testing I did:
1 rigid to 50 objs = 0m:16s
1 rigid to 100 objs = 0m:33s
1 rigid to 150 objs = 0m:49s
1 rigid to 200 objs = 1m:07s
1 rigid to 250 objs = 1m:23s
1 rigid to 500 objs = 2m:58s
1 rigid to 1000 objs = 5m:52s
1 rigid to 2000 objs = 12m:02s
1 rigid to 5000 objs = 36m:52s

Jul 8 2020, 11:11 PM · Performance, Dependency Graph, Nodes & Physics, BF Blender