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Displacement modifier clamps negative values if used with 32bit map
Closed, InvalidPublic

Description

Windows 10 / GTX1060

Broken: 2.81a, 2.82beta, 2.83alpha

short: 32bit displacement map seems to be clamped using displacement modifier. Works fine connected to shader nodes and rendered using Cycles.

long: We are working with displacement maps generated in Substance Painter. If exported in 16bit format, everything is fine. If we need more precision and exported the same to a 32bit format (tiff or exr), the displacement modifier renders strange clamps: every valley disappears and is not displaced at all, only the positive values are used. If you connect the same 32bit map to a Cycles material output node (displace on shader level), it is rendered fine.

Attached examples use the same texture, switch to rendered viewport in test_using_shader.blend .

Event Timeline

Richard Antalik (ISS) changed the task status from Needs Triage to Confirmed.Mon, Jan 13, 10:49 PM
Bastien Montagne (mont29) claimed this task.

Bah… spent two hours following the code to end up discovering that this is just a stupid option in texture's Color settings, called Clamp… yeah… So no bug here, behaving as expected.

Sorry, Bastien. I didn't know that such an option existed. At least I don't understand why it is turned on by default? It is like, loose half off posibble values by default (31bit float?!).