Regression: Triangle edges visible (ray/triangle intersection issue?) #97027

New Issue

Simon Wendsche · 2022-04-04T13:38:41+02:00

Simon Wendsche commented

2022-04-04 13:38:41 +02:00

System Information
Operating system: Windows

Blender Version
Broken: 3.1.0, 3.1.2
Worked: 3.0

Pretty sure this is caused by 74afc86d4b [it certainly broke between Jan24th and Jan31st]

Short description of error
A cube with orthographic camera pointed at it shows visible black edges around triangles.
The camera sits precisely above the cube (same X/Y floating point coordinates). If the cube or the camera are moved slightly, the problem vanishes (however, if both are moved the same amount, the problem stays).

This might point to a regression in the ray/triangle intersection code in regards to floating point precision issues.

Exact steps for others to reproduce the error

Open this file: diagonal_line.blend
Press F12 - a black diagonal line will be visible

Output from Blender 3.1.2:

Output from Blender 3.0:

**System Information** Operating system: Windows **Blender Version** Broken: 3.1.0, 3.1.2 Worked: 3.0 Pretty sure this is caused by 74afc86d4b [it certainly broke between Jan24th and Jan31st] **Short description of error** A cube with orthographic camera pointed at it shows visible black edges around triangles. The camera sits precisely above the cube (same X/Y floating point coordinates). If the cube or the camera are moved slightly, the problem vanishes (however, if both are moved the same amount, the problem stays). This might point to a regression in the ray/triangle intersection code in regards to floating point precision issues. **Exact steps for others to reproduce the error** * Open this file: [diagonal_line.blend](https://archive.blender.org/developer/F12969277/diagonal_line.blend) * Press F12 - a black diagonal line will be visible Output from Blender 3.1.2: ![render_result.png](https://archive.blender.org/developer/F12969274/render_result.png) Output from Blender 3.0: ![render_result_blender_3.0.png](https://archive.blender.org/developer/F12969284/render_result_blender_3.0.png)

Simon Wendsche commented

2022-04-04 13:38:41 +02:00

Added subscriber: @BYOB

Omar Emara commented

2022-04-04 14:07:33 +02:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-04-04 14:07:33 +02:00

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

Omar Emara commented

2022-04-04 14:07:33 +02:00

Can confirm. Minimal file to reproduce the issue. Default everything with 1 sample, denoising off. Plane with an orthographic camera.

cyclesDiagonalLine.blend

Can confirm. Minimal file to reproduce the issue. Default everything with 1 sample, denoising off. Plane with an orthographic camera. [cyclesDiagonalLine.blend](https://archive.blender.org/developer/F12969380/cyclesDiagonalLine.blend)

Philipp Oeser commented

2022-04-14 11:25:08 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-04-14 11:25:08 +02:00

Pretty sure this is caused by 74afc86d4b [it certainly broke between Jan24th and Jan31st]
Might be the new limitation we have to live with, but until further notice, will set to high prio since it is a regression on first sight.

Pretty sure this is caused by 74afc86d4b [it certainly broke between Jan24th and Jan31st] Might be the new limitation we have to live with, but until further notice, will set to high prio since it is a regression on first sight.

Philipp Oeser changed title from ~~Triangle edges visible (ray/triangle intersection issue?)~~ to Regression: Triangle edges visible (ray/triangle intersection issue?)

2022-04-14 11:25:25 +02:00

Fernando Alcala commented

2022-04-15 00:50:21 +02:00

Added subscriber: @Fernando-Alcala