Particle Hair - Density texture bug #39708

New Issue

Pawel Swierczynski · 2014-04-13T22:22:13+02:00

2014-04-13 22:22:13 +02:00

System Information
WIn7 x64
nVidia GF GTX 660

Blender Version
Broken: 2.7
Worked: 2.6

Short description of error

When I connect a texture to Particle/Hair Density parameter every time I click some, any button in Texture tab (or texture slot in PArticle tab) the position of hair strands changes.

Exact steps for others to reproduce the error

Create any mesh (box will be fine), and a small plane which will take place of a feather
Create Particle System, change:

from Emiter to Hair (Hair Length: 0.3 will do)
Render --> Object --> Dupli Object: the plane mesh you created
Textures --> click New
having it selected go to Textures tab, to Influence and click Density.

Attached blend file has it all set up.

Particle_hair_Density_bug.blend

**System Information** WIn7 x64 nVidia GF GTX 660 **Blender Version** Broken: 2.7 Worked: 2.6 **Short description of error** When I connect a texture to Particle/Hair Density parameter every time I click some, any button in Texture tab (or texture slot in PArticle tab) the position of hair strands changes. **Exact steps for others to reproduce the error** 1. Create any mesh (box will be fine), and a small plane which will take place of a feather 2. Create Particle System, change: - from Emiter to Hair (Hair Length: 0.3 will do) - Render --> Object --> Dupli Object: the plane mesh you created - Textures --> click New - having it selected go to Textures tab, to Influence and click Density. Attached blend file has it all set up. [Particle_hair_Density_bug.blend](https://archive.blender.org/developer/F84777/Particle_hair_Density_bug.blend)

Pawel Swierczynski commented

2014-04-13 22:22:13 +02:00

Changed status to: 'Open'

Pawel Swierczynski commented

2014-04-13 22:22:13 +02:00

Added subscriber: @PawelSwierczynski

Pawel Swierczynski commented

2014-04-13 22:24:17 +02:00

The screenshot below shows what`s happening with hair

The screenshot below shows what`s happening with hair ![blender_nuts.jpg](https://archive.blender.org/developer/F84778/blender_nuts.jpg)

Lukas Tönne was assigned by Bastien Montagne

2014-04-13 23:03:14 +02:00

Bastien Montagne commented

2014-04-13 23:03:14 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2014-04-13 23:03:14 +02:00

Lukas, in case you feel like crunching hairy issues again… :/

Bartosz Moniewski commented

2014-05-12 10:32:56 +02:00

Added subscribers: @ideasman42, @BartekMoniewski

Antonis Ryakiotakis commented

2014-05-16 00:33:58 +02:00

Added subscriber: @Psy-Fi

Antonis Ryakiotakis commented

2014-05-16 00:33:58 +02:00

I am not sure I understand the problem...As far as I have seen, textures -should- update the particle when tweaked. I just did a commit that avoids updating when the active texture is changed in the particle tab but I don't think changing the texture settings otherwise should not update.. Do I miss something here?

What I have seen however is that changing between textures in the particle tab strangely only updates half the sphere each time.

I am not sure I understand the problem...As far as I have seen, textures -should- update the particle when tweaked. I just did a commit that avoids updating when the active texture is changed in the particle tab but I don't think changing the texture settings otherwise should not update.. Do I miss something here? What I *have* seen however is that changing between textures in the particle tab strangely only updates half the sphere each time.

Pawel Swierczynski commented

2014-05-16 13:48:15 +02:00

The problem here is that it updates itself when you click literally anything not necessarily involving texture.
And even if it should, the change shouldn`t be so dramatic, unpredictable, etc.

Look at the screenshots Ive uploaded. The changes didnt happen because I changed "density". I clicked some irrelevant checkbox somewhere. Also the density map covers almost the whole head where you can see there are totally bald areas, not to mention weird, changing amounts of feathers.

The problem here is that it updates itself when you click literally **anything** not necessarily involving texture. And even if it should, the change shouldn`t be so dramatic, unpredictable, etc. Look at the screenshots I`ve uploaded. The changes didn`t happen because I changed "density". I clicked some irrelevant checkbox somewhere. Also the density map covers almost the whole head where you can see there are totally bald areas, not to mention weird, changing amounts of feathers.

Antonis Ryakiotakis commented

2014-05-16 16:58:58 +02:00

I can see the problem in the screenshot but it would help if the actual test file had a similar behaviour (which it doesn't, each "update" does the whole sphere). I can see how it would be nice for updates to only refresh the relevant areas though.

Sebstian commented

2014-05-18 15:34:07 +02:00

Added subscriber: @bosman

Sebstian commented

2014-05-18 15:34:07 +02:00

@Psy-Fi the problem is when influence=>density (texture) is ticked. Every time you click for example influence=>general=>time or some other texture/particle system settings like "hair lenght" (even without change the value) it exactly looks like particle system changes seeds value (seed is still "0", but hair change their location).

When influence=>density (texture) is unticked everything is ok.

@Psy-Fi the problem is when influence=>density (texture) is ticked. Every time you click for example influence=>general=>time or some other texture/particle system settings like "hair lenght" (even without change the value) it exactly looks like particle system changes seeds value (seed is still "0", but hair change their location). When influence=>density (texture) is unticked everything is ok.

Lukas Tönne removed their assignment 2014-06-06 13:03:57 +02:00

Antonis Ryakiotakis was assigned by Lukas Tönne

2014-06-06 13:03:57 +02:00

Lukas Tönne commented

2014-06-06 13:03:57 +02:00

Added subscriber: @LukasTonne

Lukas Tönne commented

2014-06-06 13:03:57 +02:00

@Psy-Fi: Assigning to you in case you have an idea. But imo we can close as TODO, spending time on these issues seems like a waste.

Antonis Ryakiotakis commented

2014-06-06 13:49:21 +02:00

Changed status from 'Open' to: 'Archived'

Antonis Ryakiotakis closed this issue

2014-06-06 13:49:21 +02:00

Antonis Ryakiotakis commented

2014-06-06 13:49:21 +02:00

Yes, this looks more like a todo actually, it requires being able to internally separate which slots should get full recalculation and which should not.

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Particle Hair - Density texture bug #39708