Fix #109254: Voronoi Distance Output Clamps at 8.0 with low Minkowski Exponents #109286

Hoshinova · 2023-06-23T13:09:36+02:00

Hoshinova commented

2023-06-23 13:09:36 +02:00

This fixes #109254 for F1 and F2, the fix doesn't work for Smooth F1.

Hoshinova added 1 commit 2023-06-23 13:09:43 +02:00

-- Fix F1 and F2 clamping at 8.0 57a62a0787

Hoshinova requested review from Omar Emara 2023-06-23 13:09:58 +02:00

Iliya Katushenock added the

Interest

Render & Cycles

label 2023-06-23 13:10:40 +02:00

Hoshinova commented

2023-06-23 13:12:56 +02:00

The problem with Smooth F1 is that the 8.0 seems to be the only constant where the smooth interpolation works correctly. So I thought you might know how to change the interpolation logic to make it work with the analytically computed max_distance.

And to be sure were on the same page params.max_distance is calculated like this:
params.max_distance = voronoi_distance(vec3(0.0), vec3(0.5 + 0.5 * params.randomness), params);

The problem with Smooth F1 is that the 8.0 seems to be the only constant where the smooth interpolation works correctly. So I thought you might know how to change the interpolation logic to make it work with the analytically computed max_distance. And to be sure were on the same page `params.max_distance` is calculated like this: `params.max_distance = voronoi_distance(vec3(0.0), vec3(0.5 + 0.5 * params.randomness), params);`

Hans Goudey changed title from ~~WIP: Fix #109254~~ to WIP: Fix #109254: Voronoi Distance Output Clamps at 8.0 with low Minkowski Exponents

2023-06-23 13:29:21 +02:00

Hoshinova added 2 commits 2023-06-24 21:34:42 +02:00

Merge branch 'main' into db c0657211cc

-- Fix Smooth F1 in GLSL except for 1D and 2D Chebychev 5d145a64e2

Hoshinova commented

2023-06-24 21:40:15 +02:00

@OmarEmaraDev I narrowed down the problem a bit.

Changing float smoothDistance = 8.0; to float smoothDistance = params.max_distance; fixes the problem for most cases... except for the 1D Smooth F1 and 2D Smooth F1 + Chebychev Color and Position outputs for some reason.

I only applied the Smooth F1 fix to the EEVEE (GLSL) version to make it easier to compare to the original version, which is still used in Cylces.

Test file demonstrating differences:
Voronoi_Test_File.blend

As can be seen in the test file there is a slight difference between the output in EEVEE and Cycles for the 1D Smooth F1 and 2D Smooth F1 + Chebychev Color and Position outputs.

@OmarEmaraDev I narrowed down the problem a bit. Changing `float smoothDistance = 8.0;` to `float smoothDistance = params.max_distance;` fixes the problem for most cases... except for the `1D Smooth F1` and `2D Smooth F1 + Chebychev` `Color` and `Position` outputs for some reason. I only applied the Smooth F1 fix to the EEVEE (GLSL) version to make it easier to compare to the original version, which is still used in Cylces. Test file demonstrating differences: [Voronoi_Test_File.blend](/attachments/e2ae5177-ece5-443c-a5ce-985cd5a59afd) As can be seen in the test file there is a slight difference between the output in EEVEE and Cycles for the `1D Smooth F1` and `2D Smooth F1 + Chebychev` `Color` and `Position` outputs.

Voronoi_Test_File.blend

6.0 MiB

Hoshinova reviewed 2023-06-24 21:41:20 +02:00

source/blender/gpu/shaders/material/gpu_shader_material_voronoi.glsl Outdated

						
				@ -157,3 +157,3 @@

				  float localPosition = coord - cellPosition;

				  float smoothDistance = 8.0;

				  float smoothDistance = params.max_distance;

Hoshinova commented

2023-06-24 21:41:20 +02:00

Slightly changes Color and Position outputs for 1D Smooth F1 and 2D Smooth F1 + Chebychev for some reason.

Slightly changes `Color` and `Position` outputs for `1D Smooth F1` and `2D Smooth F1 + Chebychev` for some reason.

Hoshinova commented

2023-06-25 19:48:45 +02:00

Changing it further to float smoothDistance = params.max_distance + 8.0; also fixes it for those cases.

Changing it further to `float smoothDistance = params.max_distance + 8.0;` also fixes it for those cases.

Hoshinova marked this conversation as resolved

Hoshinova added 1 commit 2023-06-25 19:31:15 +02:00

-- Fix Smooth F1 by adding 8.0 to params.max_distance 586d8dd66c

Hoshinova commented

2023-06-25 19:40:27 +02:00

@OmarEmaraDev
Changing float smoothDistance = params.max_distance; to float smoothDistance = params.max_distance + 8.0; fixes the issues for the 1D Smooth F1 and 2D Smooth F1 + Chebychev Color and Position outputs now.
I'm not sure why it works, my guess is that the smooth interpolation logic only works when the initial value of smoothDistance is significantly larger than params.max_distance.

It works now from a user perspective, the question is whether it makes sense regarding the whole Smooth F1 calculation logic or if it's just mere coincidence that it works.

@OmarEmaraDev Changing `float smoothDistance = params.max_distance;` to `float smoothDistance = params.max_distance + 8.0;` fixes the issues for the `1D Smooth F1` and `2D Smooth F1 + Chebychev` `Color` and `Position` outputs now. I'm not sure why it works, my guess is that the smooth interpolation logic only works when the initial value of `smoothDistance ` is significantly larger than `params.max_distance`. It works now from a user perspective, the question is whether it makes sense regarding the whole Smooth F1 calculation logic or if it's just mere coincidence that it works.

Hoshinova added 1 commit 2023-07-06 19:01:56 +02:00

-- Set initial values FLT_MAX instead of 8.0 016bc5352e

-- Initialize h to 1 for first iteration in Smooth F1

Omar Emara requested changes 2023-07-06 19:18:26 +02:00

intern/cycles/kernel/osl/shaders/node_voronoi.h Outdated

						
				@ -8,6 +8,7 @@

				#include "vector4.h"

				#define vector3 point

				#define FLT_MAX 3.402823466e+38  // max value

Omar Emara commented

2023-07-06 19:18:00 +02:00

Move that to stdcycles.h.

Move that to `stdcycles.h`.

Hoshinova marked this conversation as resolved

source/blender/gpu/shaders/material/gpu_shader_material_voronoi.glsl Outdated

						
				@ -130,3 +130,3 @@

				  float localPosition = coord - cellPosition;

				  float minDistance = 8.0;

				  float minDistance = FLT_MAX;

Omar Emara commented

2023-07-06 19:09:06 +02:00

Add at the top:

#pragma BLENDER_REQUIRE(gpu_shader_utildefines_lib.glsl)

Add at the top: ``` #pragma BLENDER_REQUIRE(gpu_shader_utildefines_lib.glsl) ```

Hoshinova marked this conversation as resolved

Hoshinova added 1 commit 2023-07-06 19:27:16 +02:00

BLENDER_SOURCE_CODE_COMMIT commit message number: 9

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Omar Emara commented

2023-07-06 19:29:29 +02:00

@blender-bot package

Blender Bot commented

2023-07-06 19:29:32 +02:00

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR109286) when ready.

Hoshinova added 2 commits 2023-07-06 19:44:57 +02:00

Merge branch 'main' into db cbd1a6cca7

BLENDER_SOURCE_CODE_COMMIT commit message number: 10

buildbot/vexp-code-patch-coordinator Build done.

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Omar Emara commented

2023-07-06 19:47:28 +02:00

@blender-bot package

Blender Bot commented

2023-07-06 19:47:32 +02:00

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR109286) when ready.

Hoshinova changed title from ~~WIP: Fix #109254: Voronoi Distance Output Clamps at 8.0 with low Minkowski Exponents~~ to Fix #109254: Voronoi Distance Output Clamps at 8.0 with low Minkowski Exponents

2023-07-06 21:18:09 +02:00

Omar Emara requested changes 2023-07-06 21:48:52 +02:00

Omar Emara left a comment

This produces artifacts for the smooth version.

This produces artifacts for the smooth version. ![20230706-224700.png](/attachments/43eb029a-c193-4cfe-b070-f82fcd2ef3ec)

20230706-224700.png

382 KiB

Hoshinova added 1 commit 2023-07-07 18:21:55 +02:00

-- Fix Smooth F1 artifacts

buildbot/vexp-code-patch-coordinator Build done.

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1261c01800