Wall eye stereo has no depth in orthographic projection
Hello - When viewing a molecule in wall-eye stereo and orthographic projection, the scene is "flat", i.e. the L and R images are identical. Perspective projection works as expected. Is there a workaround? Chimera 1.12 (41617) Mac OS X 10.11.16, NVIDIA GeForce GT 750M Thanks! Boris
Stereo views derive from binocular vision where the left and right eyes see slightly different orientations of the same scene. Perspective projects approximates the positions of the two eyes and generate two images that differ by a shearing transformation, and you get the stereo effect. Orthographic projection effectively places the eye infinitely far away in the viewing direction, so the views for left and right are identical, and you do not get the stereo effect. Thus, stereo viewing and orthographic projection are inherently incompatible and should not be used together. Conrad On 10/19/2017 8:04 AM, Boris Steipe wrote:
Hello -
When viewing a molecule in wall-eye stereo and orthographic projection, the scene is "flat", i.e. the L and R images are identical. Perspective projection works as expected.
Is there a workaround?
Chimera 1.12 (41617) Mac OS X 10.11.16, NVIDIA GeForce GT 750M
Thanks! Boris _______________________________________________ Chimera-users mailing list: Chimera-users@cgl.ucsf.edu Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users
Thanks Conrad - has this always been coded this way? I seem to remember that I used orthographic mode (years? ago) when the perspective mode overemphasized depth - which is what I was trying to solve in the first place. Thus the workaround seem to be to increase the distance to screen in orthographic mode - something like 80cm gives me about the right depth-to-width ratio on B-DNA. Cheers, Boris
On Oct 19, 2017, at 1:23 PM, Conrad Huang <conrad@cgl.ucsf.edu> wrote:
Stereo views derive from binocular vision where the left and right eyes see slightly different orientations of the same scene. Perspective projects approximates the positions of the two eyes and generate two images that differ by a shearing transformation, and you get the stereo effect. Orthographic projection effectively places the eye infinitely far away in the viewing direction, so the views for left and right are identical, and you do not get the stereo effect. Thus, stereo viewing and orthographic projection are inherently incompatible and should not be used together.
Conrad
On 10/19/2017 8:04 AM, Boris Steipe wrote:
Hello - When viewing a molecule in wall-eye stereo and orthographic projection, the scene is "flat", i.e. the L and R images are identical. Perspective projection works as expected. Is there a workaround? Chimera 1.12 (41617) Mac OS X 10.11.16, NVIDIA GeForce GT 750M Thanks! Boris _______________________________________________ Chimera-users mailing list: Chimera-users@cgl.ucsf.edu Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users
Hi Boris, You could try adjusting the field-of-view angle in the perspective projection. This can be adjusted with command “set fieldOfView” or in the Camera tool (one of the tabs in the same GUI as the Side View). <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/set.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/sideview.html#camera> I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco
On Oct 19, 2017, at 10:38 AM, Boris Steipe <boris.steipe@utoronto.ca> wrote:
Thanks Conrad - has this always been coded this way? I seem to remember that I used orthographic mode (years? ago) when the perspective mode overemphasized depth - which is what I was trying to solve in the first place.
Thus the workaround seem to be to increase the distance to screen in orthographic mode - something like 80cm gives me about the right depth-to-width ratio on B-DNA.
Cheers, Boris
On Oct 19, 2017, at 1:23 PM, Conrad Huang <conrad@cgl.ucsf.edu> wrote:
Stereo views derive from binocular vision where the left and right eyes see slightly different orientations of the same scene. Perspective projects approximates the positions of the two eyes and generate two images that differ by a shearing transformation, and you get the stereo effect. Orthographic projection effectively places the eye infinitely far away in the viewing direction, so the views for left and right are identical, and you do not get the stereo effect. Thus, stereo viewing and orthographic projection are inherently incompatible and should not be used together.
Conrad
On 10/19/2017 8:04 AM, Boris Steipe wrote:
Hello - When viewing a molecule in wall-eye stereo and orthographic projection, the scene is "flat", i.e. the L and R images are identical. Perspective projection works as expected. Is there a workaround? Chimera 1.12 (41617) Mac OS X 10.11.16, NVIDIA GeForce GT 750M Thanks! Boris
Hi, Boris. I wrote the stereo code a VERY long time ago and I think several others have changed various parts since. Still, I'm a little surprised that the distance to screen has any effect in orthographic projection. In perspective projection, the parameter obviously makes a big difference. In code, all three stereo parameters in the Camera tab are combined to determine the effective field of view, and therefore the depth effect. Rather than playing with those numeric parameters, you can also use the Side View tab to get immediate feedback on changes. The documentation for Side View (https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/topview.html) describes the various controls, but here is a short summary. Switch from "right" to "top" view by changing the "Side:" option just above the Help button, then choose a stereo mode (e.g., wall-eye stereo) by double clicking on the eye and selecting from the menu. That should show a rectangular eye with separate viewing regions for the left and right eyes, depicted by red lines. These red lines are draggable and the graphics view should immediately reflect changes so you can interactively choose your preferred field of view/depth effect. The eye, yellow hither and yon clipping plane lines, and the dotted focal plane line are also draggable (left-right) to control the view size, depth-cue effects, and front-back positioning respectively. Hope this helps. Conrad On 10/19/2017 10:38 AM, Boris Steipe wrote:
Thanks Conrad - has this always been coded this way? I seem to remember that I used orthographic mode (years? ago) when the perspective mode overemphasized depth - which is what I was trying to solve in the first place.
Thus the workaround seem to be to increase the distance to screen in orthographic mode - something like 80cm gives me about the right depth-to-width ratio on B-DNA.
Cheers, Boris
On Oct 19, 2017, at 1:23 PM, Conrad Huang <conrad@cgl.ucsf.edu> wrote:
Stereo views derive from binocular vision where the left and right eyes see slightly different orientations of the same scene. Perspective projects approximates the positions of the two eyes and generate two images that differ by a shearing transformation, and you get the stereo effect. Orthographic projection effectively places the eye infinitely far away in the viewing direction, so the views for left and right are identical, and you do not get the stereo effect. Thus, stereo viewing and orthographic projection are inherently incompatible and should not be used together.
Conrad
On 10/19/2017 8:04 AM, Boris Steipe wrote:
Hello - When viewing a molecule in wall-eye stereo and orthographic projection, the scene is "flat", i.e. the L and R images are identical. Perspective projection works as expected. Is there a workaround? Chimera 1.12 (41617) Mac OS X 10.11.16, NVIDIA GeForce GT 750M Thanks! Boris _______________________________________________ Chimera-users mailing list: Chimera-users@cgl.ucsf.edu Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users
participants (3)
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Boris Steipe -
Conrad Huang -
Elaine Meng