"Attach Hair Curves to Surface" asset incorrectly sets surface UV coordinates #111354

New Issue

Closed

opened 2023-08-21 18:13:52 +02:00 by Eugene-Kuznetsov · 5 comments

Eugene-Kuznetsov commented

2023-08-21 18:13:52 +02:00

Contributor

Attached screenshot displays a portion of the "Attach Hair Curves to Surface" asset, as included in 3.6.

You can see two different nodes "Store Named Attribute" writing attributes named "surface_uv_coordinate". Notice that the same input received by the second node is also returned out of the node group through the port named "Surface Normal". It is, in fact, the surface normal. The second node should be writing to "surface_normal" and its type should be "Vector", not "2D Vector".

Since the second node overwrites the (valid) attachment UV coordinate written by the first one, hair curves end up with incorrect and possibly illegal, e.g. negative, surface_uv_coordinate attributes, leading to all sorts of weird behavior later on (for example, parts of hair object disappear when you try to convert them into particle hair, because strands with illegal UV coordinates are thrown away during conversion.)

Attached screenshot displays a portion of the "Attach Hair Curves to Surface" asset, as included in 3.6. You can see two different nodes "Store Named Attribute" writing attributes named "surface_uv_coordinate". Notice that the same input received by the second node is also returned out of the node group through the port named "Surface Normal". It is, in fact, the surface normal. The second node should be writing to "surface_normal" and its type should be "Vector", not "2D Vector". Since the second node overwrites the (valid) attachment UV coordinate written by the first one, hair curves end up with incorrect and possibly illegal, e.g. negative, surface_uv_coordinate attributes, leading to all sorts of weird behavior later on (for example, parts of hair object disappear when you try to convert them into particle hair, because strands with illegal UV coordinates are thrown away during conversion.)

Screenshot from 2023-08-21 09-00-46.png

286 KiB

Screenshot from 2023-08-21 09-00-46.png

Eugene-Kuznetsov added the

labels 2023-08-21 18:13:53 +02:00

YimingWu commented

2023-08-22 03:32:05 +02:00

Member

Probably same as: #110706

Also might be related: #107856

Probably same as: #110706 Also might be related: #107856

Philipp Oeser commented

2023-08-29 13:29:25 +02:00

Member

This indeed looks wrong.

@SimonThommes : mind sharing your wisdom here?

This indeed looks wrong. @SimonThommes : mind sharing your wisdom here?

Philipp Oeser added

Nodes & Physics

and removed

labels 2023-08-29 13:29:52 +02:00

Simon Thommes commented

2023-09-04 12:48:24 +02:00

Member

Yea, this is just a plain mistake that slipped through, it seems. Will fix for 4.0 and 3.6

Yea, this is just a plain mistake that slipped through, it seems. Will fix for 4.0 and 3.6

Simon Thommes commented

2023-09-04 12:51:51 +02:00

Member

Probably same as: #110706

Also might be related: #107856

Both these issues are not related afaict.

> Probably same as: #110706 > > Also might be related: #107856 Both these issues are not related afaict.

Simon Thommes commented

2023-09-04 15:11:13 +02:00

Member

@Eugene-Kuznetsov in your file you can fix it by replacing the surface_uv_coordinate in the second (right) Store Named Attribute node with surface_normal and changing the data type from 2D Vector to Vector.

I fixed this for 4.0 and 3.6 LTS, so it will be included in those upcoming releases.

Note: Due to the fact how the append and reuse functionality works, that means files using a broken version of this asset will not automatically receive the fixed version. Not for the existing instances of the node, nor for new instances dragged in from the asset browser.

@Eugene-Kuznetsov in your file you can fix it by replacing the `surface_uv_coordinate` in the second (right) `Store Named Attribute` node with `surface_normal` and changing the data type from `2D Vector` to `Vector`. I fixed this for 4.0 and 3.6 LTS, so it will be included in those upcoming releases. Note: Due to the fact how the `append and reuse` functionality works, that means files using a broken version of this asset will not automatically receive the fixed version. Not for the existing instances of the node, nor for new instances dragged in from the asset browser.

Simon Thommes closed this issue

2023-09-04 15:11:16 +02:00

Blender Bot added

and removed

labels 2023-09-04 15:11:18 +02:00

Simon Thommes added

and removed

labels 2023-09-04 15:14:23 +02:00

Sign in to join this conversation.

No Label

Animation & Rigging

Asset Browser Project Overview

Automated Testing

Blender Asset Bundle

Dependency Graph

Development Management

EEVEE & Viewport

Images & Movies

Motion Tracking

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Render Pipeline

Sculpt, Paint & Texture

Video Sequencer

Virtual Reality

Blender 2.8 Project

Milestone 1: Basic, Local Asset Browser

Good First Issue

Animation & Rigging

Development Management

EEVEE & Viewport

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Sculpt, Paint & Texture

Needs Info from Developers

Needs Information from User

No Milestone

No project

No Assignees

4 Participants

Notifications

Due Date

The due date is invalid or out of range. Please use the format 'yyyy-mm-dd'.

No due date set.

Dependencies

No dependencies set.

Reference: blender/blender#111354

No description provided.