Blender Exporter: Camera's Y position gets negated.

[kayomarz]

Blender exporter seems to negate the value of the y position of the camera.

Note: This is not related to the Flip YZ feature.

Apart from this, the exporter works great.

Blender version: 2.69.0 (r60991)
Three.js revision: 63

The property pane of the default blender scene shows the camera position as: 7.48113, -6.50764, 5.34367

Blender exporter exports it as: 7.48113, 6.50764, 5.34367

Following is a snipped of the default blender scene exported using blender exporter. (Note that Flip YZ is enabled.)

    "Camera" : {
        "type"  : "PerspectiveCamera",
        "fov"   : 49.159264,
        "aspect": 1.333000,
        "near"  : 0.100000,
        "far"   : 100.000000,
        "position": [ 7.48113, 5.34367, 6.50764 ],
        "target"  : [ 0, 0, 0 ]
    }

After digging into the python code, line number 2178 shows that the y position is explicitly negated.

Wondering if there's any reason for negating it or maybe just a typo?

In what way is 5.34 a negated value? unless i'm missing something.. ?

On Fri, Dec 13, 2013 at 2:52 PM, Kayomarz notifications@github.com wrote:

Blender exporter seems to negate the value of the y position of the
camera.

Note: This is not related to the Flip YZ feature.

Apart from this, the exporter works great.

Blender version: 2.69.0 (r60991)
Three.js revision: 63

The property pane of the default blender scene shows the camera
position as: 7.48113, -6.50764, 5.34367

Blender exporter exports it as: 7.48113, 6.50764, 5.34367

Following is a snipped of the default blender scene exported using
blender exporter. (Note that Flip YZ is enabled.)

"Camera" : {
    "type"  : "PerspectiveCamera",
    "fov"   : 49.159264,
    "aspect": 1.333000,
    "near"  : 0.100000,
    "far"   : 100.000000,
    "position": [ 7.48113, 5.34367, 6.50764 ],
    "target"  : [ 0, 0, 0 ]
}

After digging into the python code, line number 2178https://github.com/mrdoob/three.js/blob/master/utils/exporters/blender/2.65/scripts/addons/io_mesh_threejs/export_threejs.py#L2178shows that the
y position is explicitly negated.

Wondering if there's any reason for negating it or maybe just a typo?

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Reply to this email directly or view it on GitHubhttps://github.com//issues/4207
.

[kayomarz]

-6.50764 gets negated to 6.50764

[mrdoob]

I'm a bit out of touch with that exporter. Maybe @joostfaassen knows what the problem is?

[kayomarz]

After removing the explicit negative sign on line 2178 it seems ok. I wonder if it's needed in some situation or might be a typo.

Line 2178:

"position"  : generate_vec3([cameraobj.location[0], -cameraobj.location[1], cameraobj.location[2]], data["flipyz"])

[mrdoob]

If you could do a few test and double check that it works, a PR with the fix would then be great :)

[kayomarz]

The reason for explicitly negating the value is unknown. Removing the negation seems to work. Making a PR incase you would like to use it.

[Mugen87]

The JSON Blender exporter has been removed with R93 (#14117).

Also see: https://threejs.org/docs/#manual/introduction/Loading-3D-models