Effect different depending on computer

Mon Dec 31, 2018 6:26 pm

same_effect_different_computer.png
same_effect_different_computer.png (127.9 KiB) Viewed 99 times

The two images above are constructed from the same video file, ISF effect (5 color gradient), params, OS (Windows), version of Magic, NVidia driver, Magic settings etc. The only differences are that top image is a desktop with a GTX970 and the bottom image is a laptop with GTX1070. I think the top image is how it is supposed to look.

Something is causing the effect to render incorrectly on the laptop.

There are 5 difference in the GL info dialogue box - these capabilities are in the laptop list but missing from the desktop:
GL_NV_clip_space_w_scaling
GL_NV_conservative_raster_pre_snap_triangles
GL_NV_shader_atomic_float64
GL_NV_texgen_reflection
GL_NVX_blend_equation_advanced_multi_draw_buffers

Given that these are missing on the desktop but the desktop seems to be rendering correctly, I doubt that this difference is important.

I have suspicions that other effects may also be rendering incorrectly on the laptop though I have more work to do to identify any. I'd be grateful if others could test this particular ISF to see
a) if my desktop actually is correct and hence my laptop wrong and,
b) if someone has a similar setup to me if they experience similar issues and,
c) can anyone think of something (obvious) I've missed and,
d) if anyone has noticed any similar rendering differences (say between GPUs or Mac/Win etc.).

Perhaps OpenGL is so complicated that I cannot hope to have an identical environment between two computers - I hope not.
Sadler
 
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Re: Effect different depending on computer

Mon Dec 31, 2018 6:41 pm

There can be slight differences in how shaders work on different systems. I've found that small things matter like decimal points, or zeros after a decimal point, or the names of some built-in functions.

I assume that your ISF gradient shader is a custom one? If so maybe post it and I'll take a look.
Eric
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Re: Effect different depending on computer

Mon Dec 31, 2018 7:15 pm

Sadler
 
Posts: 510
Joined: Sat Aug 02, 2014 7:10 pm
Location: London, UK

Re: Effect different depending on computer

Mon Dec 31, 2018 10:33 pm

Hmm I'm not sure. Is your OpenGL driver version the same on both machines?

Edit: never mind, I see that you said it's the same. Dunno. The shader seems to work fine on my machine. How much skill do you have in editing GLSL? One approach might be to try and simplify the code bit by bit until you can narrow down the issue.
Eric
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Re: Effect different depending on computer

Tue Jan 01, 2019 5:00 pm

This ISF doesn't work properly without its vertex shader file. Replacing the .vs solves the issue. Thanks for taking a look and sorry for wasting your time.
Sadler
 
Posts: 510
Joined: Sat Aug 02, 2014 7:10 pm
Location: London, UK

Re: Effect different depending on computer

Tue Jan 01, 2019 5:02 pm

No worries.
Eric
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Joined: Wed Apr 09, 2014 9:28 pm

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