Use gaea format problem?

Started by gao_jian11, April 03, 2020, 08:59:38 pm

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gao_jian11

Ladies and gentlemen, I found that gaea can't output ter, and the tif32 it outputs cannot be used for tg? What format of output does everyone use?

WAS

open exr or 32bit tiff work, but you have to manually up the amplitude in Terragen to match Gaea, it's not incorporating amplitude (which is a waste of 32bit float imo). Other heightmaps I use of terrains more or less work at disp 1 unless 8/16bit.

digitalguru

April 06, 2020, 05:56:03 pm #2 Last Edit: April 06, 2020, 06:06:29 pm by digitalguru
The displacement outputs on Gaea have been patchy at best, for quite a while what was supposedly 32bit .exr were actually 16bit.

Agree with WAS that .exr (or any 32bit output) should output values that actually represent the true height of the terrain, i.e if your terrain is 600 meters high, then the largest value in the displacement image should be 600 also. This is how Terragen does it and it is very accurate and a good fail-safe way of approaching it. I think World Machine can now output .exr in the same way.

There is a way to accurately load your Gaea displacement map in Terragen:
  • Export the displacement map from Gaea as 32bit .tif. Set Output Range to Natural Elevation.
  • Make a note of the Terrain Definition in Gaea - you need to note Height and Scale, the default values are 2600 and 5000 respectively.
  • Load the .tif into Terragen via a Heightfield Load node.
  • Connect the Heightfield Load into a Heightfield resize node. Check only Re-size in meters and set both values to 5000 (the Gaea scale value).
  • Add and connect a Heightfield adjust vertical, click Multiply Height by and set to 2600 (the Gaea height value).

This only works when output is 32bit tiff, and you can't use this workflow if you've rendered out a 32bit exr, I really don't know why - if you render out displacement maps from Mudbox in either 32bit .tif or .exr, they contain the same values.

p.s I did ask Quadspinner if they planned to output exrs in the same manner as Terragen and they replied:
"Currently, this is not directly possible at the moment. But it is in our backlog and will be implemented in the near future."

But that was about 9 months ago

SILENCER

I use this method, keeps it simple for me

TG_capture-Gaea.JPG

gao_jian11

Thank you all, I solved this problem. Treeagen does not support 32 as tif in uint format, just save it as float format.

WAS

April 11, 2020, 02:50:32 am #5 Last Edit: April 11, 2020, 02:54:21 am by WAS
Units come in three forms, no units, inches (default), and centimeters. No units works because TG reads floating point integer, which it reads as meters. I'm not sure why Gaea is saving inches or centimeters by default. Maybe a game thing, that's not standard for 3D. Seen it in drafting (printing elements and such). TG should be able to ignore units, I believe though, and still use floating point when 32bit I believe. Would just need the logic.

Additionally, I'd be careful using that method @SILENCER if your data has fine surface details, they will be exaggerated when ramping up to what "looks" like same disp in the original program. I had issues with rocks in my valley becoming spikes.

mhaze

I find a height of 2700 generally works - but check your gaea setup.

digitalguru

Quote from: digitalguru on April 06, 2020, 05:56:03 pmThere is a way to accurately load your Gaea displacement map in Terragen:
  • Export the displacement map from Gaea as 32bit .tif. Set Output Range to Natural Elevation.
  • Make a note of the Terrain Definition in Gaea - you need to note Height and Scale, the default values are 2600 and 5000 respectively.
  • Load the .tif into Terragen via a Heightfield Load node.
  • Connect the Heightfield Load into a Heightfield resize node. Check only Re-size in meters and set both values to 5000 (the Gaea scale value).
  • Add and connect a Heightfield adjust vertical, click Multiply Height by and set to 2600 (the Gaea height value).
Update - as of Gaea 1.2.1.8 this is now changed:

  • In Gaea set format under Files to Save as .exr.
  • Set Range to Remapped and Max value to the height of the terrain as defined in Terrain Definition.
  • Build in Gaea to export the .exr
  • Load the .exr into Terragen via a Heightfield Load node.
  • Connect the Heightfield Load into a Heightfield Resize node. Check only Re-size in meters and set both values the Scale value in Terrain Definition(Gaea).

Hannes

Cool, thanks. Is the exr-output better than tiff? So far your method produced the wanted detail.

digitalguru

October 10, 2021, 04:42:05 pm #9 Last Edit: October 10, 2021, 04:45:18 pm by digitalguru
If you're just going from Gaea to TG, both are valid. Exr has better compression and is more portable to a lot of apps in a modern pipeline.

I've run into situations where depending on where the .tif was written, some apps haven't read it.

p.s most apps understand that .exr is in a linear color space and will read those values correctly

WAS

If the TIFF is float or half-float, there shouldn't be any issues reading it (that data is standardized, I don't think there is any other way to interpret it). It's the extra data. Compression, layers, etc. And for some reason some readers I've come across have no legacy support. Like recently I had issues with TIFs from PS because I kept forgetting to uncheck Save Layers.