Dynamic paint sub-steps samples only brush #102122

New Issue

Damian · 2022-10-28T14:07:41+02:00

Damian commented

2022-10-28 14:07:41 +02:00

Simplified Report

An elongated subdivided plane act as a displacement dynamic paint canvas with the default settings.
An icosphere acts as a dynamic paint brush with the default settings.
The canvas is animated and the brush is fixed.
Play the animation and notice how sampling is too low, so only a few spots are painted.
Increase the sub-steps to any high number.
Notice that the sampling frequency doesn't change.

dynamicPaintSubSteps.blend

Original Report

System Information
Operating system: Windows-10-10.0.19043-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 526.47

Blender Version
Broken: version: 3.3.0, branch: master, commit date: 2022-09-06 15:39, hash: 0759f671ce
Worked: (newest version of Blender that worked as expected)

Short description of error
[Please fill out a short description of the error here]

When adding more substeps to Dynamic paint, it seems it samples only Brush when it is animated, but does not take Canvas movement into account, so, instead of getting more smooth curve, I get a dashed line in my case.

in my scene, the disc is the Canvas and it is rotating. The brush is attached to the moving bar. Basically, this is a curve drawing machine, so the result should be a smooth continuous line.
the scene is also attached.
curve drawing.blend

Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

## Simplified Report - An elongated subdivided plane act as a displacement dynamic paint canvas with the default settings. - An icosphere acts as a dynamic paint brush with the default settings. - The canvas is animated and the brush is fixed. - Play the animation and notice how sampling is too low, so only a few spots are painted. - Increase the sub-steps to any high number. - Notice that the sampling frequency doesn't change. [dynamicPaintSubSteps.blend](https://archive.blender.org/developer/F13789913/dynamicPaintSubSteps.blend) ## Original Report **System Information** Operating system: Windows-10-10.0.19043-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 526.47 **Blender Version** Broken: version: 3.3.0, branch: master, commit date: 2022-09-06 15:39, hash: `0759f671ce` Worked: (newest version of Blender that worked as expected) **Short description of error** [Please fill out a short description of the error here] When adding more substeps to Dynamic paint, it seems it samples only Brush when it is animated, but does not take Canvas movement into account, so, instead of getting more smooth curve, I get a dashed line in my case. ![image.png](https://archive.blender.org/developer/F13789709/image.png) in my scene, the disc is the Canvas and it is rotating. The brush is attached to the moving bar. Basically, this is a curve drawing machine, so the result should be a smooth continuous line. the scene is also attached. [curve drawing.blend](https://archive.blender.org/developer/F13789754/curve_drawing.blend) **Exact steps for others to reproduce the error** [Please describe the exact steps needed to reproduce the issue] [Based on the default startup or an attached .blend file (as simple as possible)]

Damian commented

2022-10-28 14:07:41 +02:00

Added subscriber: @DamianWinnichenko

Omar Emara commented

2022-10-28 14:32:35 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Omar Emara changed title from ~~Dynamic paint substeps samples only brush~~ to Dynamic paint sub-steps samples only brush

2022-10-28 14:39:13 +02:00

Damian commented

2022-10-28 18:09:05 +02:00

I know, this usually should be avoided, but I want to add another little issue here.

The amount of sub-steps in Dynamic paint is hardcoded by a maximum of 20. Which could be not enough for some fast-moving objects like debris, water splashes, etc.
I would suggest increasing the hard limit to 128-ish while keeping the soft limit around 10-ish we have right now.

I know, this usually should be avoided, but I want to add another little issue here. The amount of sub-steps in Dynamic paint is hardcoded by a maximum of 20. Which could be not enough for some fast-moving objects like debris, water splashes, etc. I would suggest increasing the hard limit to 128-ish while keeping the soft limit around 10-ish we have right now.

Philipp Oeser commented

2022-11-01 12:42:26 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-11-01 12:42:26 +01:00

Regarding substeps of brush vs. canvas:

In #84524#1096663, @lichtwerk wrote:
So after a bit of digging, this really seems like designed that way.
In code, only the brush objects are updated specifically for each subframe.

After all that digging, I found that this has been reported before, see #48797 (Dynamic Paint Sub-Steps not working when Canvas is moving).
Turns out, this was not considered a bug at that time either.

Not saying that this could not be supported, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior.
Afraid we have to close this as this bug tracker is only for bugs and errors.

For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests
For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

Will merge into #48797

Regarding substeps of brush vs. canvas: > In #84524#1096663, @lichtwerk wrote: > So after a bit of digging, this really seems like designed that way. > In code, only the brush objects are updated specifically for each subframe. > > After all that digging, I found that this has been reported before, see #48797 (Dynamic Paint Sub-Steps not working when Canvas is moving). > Turns out, this was not considered a bug at that time either. > > Not saying that this could not be supported, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. > Afraid we have to close this as this bug tracker is only for bugs and errors. > > For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests > For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug Will merge into #48797

Philipp Oeser commented

2022-11-01 12:42:37 +01:00

Closed as duplicate of #48797

Philipp Oeser closed this issue

2022-11-01 12:42:37 +01:00

Damian commented

2022-11-01 13:53:46 +01:00

In #102122#1439608, @lichtwerk wrote:
Regarding substeps of brush vs. canvas:

In #84524#1096663, @lichtwerk wrote:
So after a bit of digging, this really seems like designed that way.
In code, only the brush objects are updated specifically for each subframe.

After all that digging, I found that this has been reported before, see #48797 (Dynamic Paint Sub-Steps not working when Canvas is moving).
Turns out, this was not considered a bug at that time either.

Not saying that this could not be supported, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior.
Afraid we have to close this as this bug tracker is only for bugs and errors.

For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests
For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

Will merge into #48797

Okay then. thanks for the investigation!
For me it looked like a bug... anyway, I think this limitation must be stressed in the documentation as well to avoid frustration and misunderstanding...

Thanks again!

> In #102122#1439608, @lichtwerk wrote: > Regarding substeps of brush vs. canvas: > >> In #84524#1096663, @lichtwerk wrote: >> So after a bit of digging, this really seems like designed that way. >> In code, only the brush objects are updated specifically for each subframe. >> >> After all that digging, I found that this has been reported before, see #48797 (Dynamic Paint Sub-Steps not working when Canvas is moving). >> Turns out, this was not considered a bug at that time either. >> >> Not saying that this could not be supported, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. >> Afraid we have to close this as this bug tracker is only for bugs and errors. >> >> For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests >> For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug > > Will merge into #48797 Okay then. thanks for the investigation! For me it looked like a bug... anyway, I think this limitation must be stressed in the documentation as well to avoid frustration and misunderstanding... Thanks again!

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Dynamic paint sub-steps samples only brush #102122

Simplified Report

Original Report