Decrease shader TIME rollover to 30 seconds on mobile platforms
#59990
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Calinou
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doc/classes/ProjectSettings.xml
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| @@ -1756,6 +1756,10 @@ | |||
| <member name="rendering/limits/spatial_indexer/update_iterations_per_frame" type="int" setter="" getter="" default="10"> | |||
| </member> | |||
| <member name="rendering/limits/time/time_rollover_secs" type="float" setter="" getter="" default="3600"> | |||
| When the [code]TIME[/code] shader built-in variable is incremented, it will roll over to [code]0.0[/code] when the value specified in [member rendering/limits/time/time_rollover_secs] is exceeded (in seconds). Since large floating-point values are less precise than small floating-point values, this should be set as low as possible to maximize the precision of the [code]TIME[/code] built-in variable in shaders. However, if this is set too low, shader animations may appear to restart from the beginning while the project is running. | |||
| </member> | |||
| <member name="rendering/limits/time/time_rollover_secs.mobile" type="int" setter="" getter="" default="30"> | |||
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The property hint doesn't seem to apply to the override, it's typed as int (and likely doesn't have a range slider).
Also, why 30 seconds specifically? That sounds really low.
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Also, why 30 seconds specifically? That sounds really low.
@clayjohn recommended to use 30 instead of 60, as 16-bit floating point precision gets low very quickly. If the rollover time was 60, the worst precision you'd get would be 0.03, and this is already too imprecise for many shader effects: https://en.wikipedia.org/wiki/Half-precision_floating-point_format#Precision_limitations
In comparison, this is not nearly as much of an issue with 32-bit floats.
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In general, this looks good. Before merging we should double check what the behaviour on the vulkan-mobile backend is (e.g. does it default to 16p or 32p floats) |
#52500 wasn't merged, so it might still be defaulting to 32-bit floats right now. |
This avoids precision issues that became obvious when exporting a project to a mobile platform. Shader animations will have to loop over 30 seconds to avoid visual discrepancies when `TIME` is reset back to 0.
Calinou
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Some notes:
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This avoids precision issues that became obvious when exporting a project to a mobile platform.
Shader animations will have to loop over 30 seconds to avoid visual discrepancies when
TIMEis reset back to 0.