POV-Ray

The Persistence of Vision Raytracer (POV-Ray).

This is the legacy Bug Tracking System for the POV-Ray project. Bugs listed here are being migrated to our github issue tracker. Please refer to that for new reports or updates to existing ones on this system.

Tasklist

FS#67 - alpha channel in image map is ignored for shadows

Attached to Project: POV-Ray
Opened by Christoph Lipka (clipka) - Wednesday, 11 November 2009, 19:00 GMT
Last edited by Christoph Lipka (clipka) - Saturday, 19 June 2010, 12:47 GMT
Task Type Definite Bug
Category Backend → Texture/Material/Finish
Status Closed
Assigned To Christoph Lipka (clipka)
Operating System All
Severity Low
Priority Normal
Reported Version All
Due in Version 3.70 beta 37
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

In the following scene, the mesh object will always cast a fully-opaque shadow, even if the image has an alpha channel:

camera {
  location  <0.5, 1.0, -1.0>
  look_at   <0.5, 0.0,  0.5>
}

light_source { <0, 30, 0> color rgb 1 }

mesh {
    triangle { <0,0,0>, <1,0,0>, <1,0,1> uv_vectors <0,0>, <1,0>, <1,1> }
    triangle { <0,0,0>, <1,0,1>, <0,0,1> uv_vectors <0,0>, <1,1>, <0,1> }
    texture { pigment { uv_mapping image_map {png "FOOBAR.png"} } }
}

plane { y, -0.1 pigment { color rgb 1 } }

The following modification to the texture will give the expected results:

    texture { uv_mapping pigment { image_map {png "FOOBAR.png"} } }

The problem can be observed with both POV-Ray 3.7 (tested with beta.34), as well as 3.6 (tested with 3.6.2).

This task depends upon

Closed by  Christoph Lipka (clipka)
Saturday, 19 June 2010, 12:47 GMT
Reason for closing:  Fixed
Comment by Christoph Lipka (clipka) - Wednesday, 11 November 2009, 19:05 GMT

First analysis shows that the parser erroneously identifies the problematic construct as an opaque texture, setting a flag on the object that causes the shadow handling code to completely bypass examination of the object's materials.

Comment by Christoph Lipka (clipka) - Friday, 26 March 2010, 17:35 GMT
  • Field changed: Status (Assigned → Requires testing)
  • Field changed: Percent Complete (0% → 100%)

fixed in change #4933

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