Obscura (Pinhole camera) produces incorrect results with emission texture #36979

New Issue

Nathan Brader · 2013-10-07T01:50:31+02:00

Nathan Brader commented

2013-10-07 01:50:31 +02:00

%%%--- Operating System, Graphics card ---
Windows 7, NVIDIA GeForce GTX 660

- Blender version with error, and version that worked ---

error in 2.68a

- Short description of error ---

In cycles render: when allowing light, emitted by a texture, to pass through a small hole, the image projected onto a face on the other side is physically incorrect.

- Steps for others to reproduce the error (preferably based on attached .blend file) ---

The attached "obscura_failure.blend" shows the emission texture on the right and the rendered the result on the left.%%%

%%%--- Operating System, Graphics card --- Windows 7, NVIDIA GeForce GTX 660 - Blender version with error, and version that worked --- error in 2.68a - Short description of error --- In cycles render: when allowing light, emitted by a texture, to pass through a small hole, the image projected onto a face on the other side is physically incorrect. - Steps for others to reproduce the error (preferably based on attached .blend file) --- The attached "obscura_failure.blend" shows the emission texture on the right and the rendered the result on the left.%%%

Nathan Brader commented

2013-10-07 01:50:31 +02:00

Changed status to: 'Open'

Nathan Brader commented

2013-10-07 02:02:14 +02:00

%%%It's difficult to establish what exactly is failing. It renders correctly when the camera views the texture directly. Light also diffusely reflects realistically from nearby diffuse faces. This bug only seems to happen when the rays pass through the aperture.%%%

Nathan Brader commented

2013-10-07 02:04:08 +02:00

%%%When viewing it through the aperture, the texture maintains that very specific distortion as it is translated and rotated in space.%%%

Nathan Brader commented

2013-10-07 02:17:05 +02:00

%%%This is what I see: http://i.imgur.com/JjCX1hv.png%%%

Victor Malherbe commented

2013-10-07 04:38:42 +02:00

%%%Same bug for me, but suprisingly it works when I disable Multiple Importance Sampling for the emitting plane. Warning though, without MIS the render will be very slow since the path tracer is having a hard time finding the light. So I guess there's something wrong with MIS, normally it's just supposed to guide the paths you sample so they find the lights more easily, but it shouldn't change the final render...%%%

Nathan Brader commented

2013-10-08 09:31:49 +02:00

%%%Victor's workaround works on my work computer but not on my home computer (where I originally found the bug).

In case it's at all relevant: My home computer has the following spec:
CPU: Intel 3rd Generation Core i5-3570K CPU (4 x 3.40GHz, Ivy Bridge, Socket 1155, 6Mb L3 Cache, Intel Turbo Boost Technology 2.0)
RAM: 16 GB
GPU: NVIDIA GeForce GTX 660
OS: Windows 7 (64-bit)

My work computer:
CPU: Intel Core i7 CPU 860 @ 2.8GHz
RAM: 3 GB
GPU: NVIDIA GeForce 310
OS: Windows 7 (32-bit)
%%%

%%%Victor's workaround works on my work computer but not on my home computer (where I originally found the bug). In case it's at all relevant: My home computer has the following spec: CPU: Intel 3rd Generation Core i5-3570K CPU (4 x 3.40GHz, Ivy Bridge, Socket 1155, 6Mb L3 Cache, Intel Turbo Boost Technology 2.0) RAM: 16 GB GPU: NVIDIA GeForce GTX 660 OS: Windows 7 (64-bit) My work computer: CPU: Intel Core i7 CPU 860 @ 2.8GHz RAM: 3 GB GPU: NVIDIA GeForce 310 OS: Windows 7 (32-bit) %%%

blender-admin commented

2014-02-07 15:09:34 +01:00

This issue was referenced by blender/blender-addons-contrib@9c83ed774b

This issue was referenced by blender/blender-addons-contrib@9c83ed774bbc7b74242df0628f1de07df8f04df7

blender-admin commented

2014-02-07 15:09:34 +01:00

This issue was referenced by 9c83ed774b

This issue was referenced by 9c83ed774bbc7b74242df0628f1de07df8f04df7

Brecht Van Lommel commented

2014-02-07 15:10:48 +01:00

Fixed now, thanks for the report.