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jefferytitan

Tools for creating HDR sprite sheets

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Hi all,

I want to make animated emission maps, so I'm looking for a tool for creating HDR sprite sheets. Is there such a thing out there? I imagine that HDR isn't a common requirement.

The sort of features I'm looking for are:

  • Can clone a frame
  • Pixel editing
  • Image effects, e.g. blur
  • Can choose how they're layed out in the sprite map, I just need vertical stacking

Any suggestions would be appreciated!

Cheers,
JT

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I imagine that HDR isn't a common requirement.

High-Dynamic-Range correct?

 

looking for a tool for creating HDR sprite sheets

No, there is no software in the world that could create a HDR sprite sheet, however it can be faked and any 2D software can fake it.

 

HDR takes 3 photos: one regular, one under exposed and last a over exposed photo of a scene. These are merged into a new image, gaining the color and sharpness of the under expose, the light from over exposed, and mapped to the regular photo.

So using a single image there is no way to create the light, just as scaling a image doesn't create the missing pixel data.

However it can be faked using 3D software light or 2D software filters and pulling known data from the image.

 

There is software that will do this to a single image for you, however it won't work on a sprite sheet as it depends on dull colors to work.

The other problem with auto tools for this is that a computer has no imagination, it can't predict what every image will look like over exposed and under exposed.

So most of the time the resulting over exposure and under exposure just cancels out, resulting in only a slightly changed image.

 

Here is a tutorial to show how it's done, remember this is only a guide you will need to study HDR and use phothos as refrence to get a good image each time: http://www.instructables.com/id/HDR-looking-effect-with-only-1-photo/

 

If you insist on using some quick tool use this versatile tool : https://hdrconverter.com/helper/ZWUwiVgFwAJIPNrpL3M3mE3CpK5wcK4F210192

You can select a filter that matches your color scheme.

Or just get Gimp/ Photoshop and just play with the filters, you are just as likely to get good results.

 

I want to make animated emission maps

What? Emission maps are black and white, HDR will have no effect. Even if the engine you are using uses color for emission the color will be so bright there will be no visible effect from HDR.

 

Edit:

Just remembered this: https://www.patreon.com/posts/behind-you-64-6122227

Some artist will disagree, however I feel they capture the HDR into a drawing style.

Edited by Scouting Ninja

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Thanks for the reply!

jefferytitan, on 23 Feb 2017 - 09:47 AM, said: I imagine that HDR isn't a common requirement. High-Dynamic-Range correct?
 

Correct.

No, there is no software in the world that could create a HDR sprite sheet, however it can be faked and any 2D software can fake it.

If that's true, it's a shame. I suspected it might be the case.

HDR takes 3 photos: one regular, one under exposed and last a over exposed photo of a scene. These are merged into a new image, gaining the color and sharpness of the under expose, the light from over exposed, and mapped to the regular photo.

I think we're on different pages here. I'm not going from source photos like a skybox, I want to make an HDR texture from scratch using drawing tools, e.g. circles, boxes, blur, etc. 

What? Emission maps are black and white, HDR will have no effect. Even if the engine you are using uses color for emission the color will be so bright there will be no visible effect from HDR.

Maybe that's something engine specific. I'm already using full colour emission maps in Unity. The problem is that using SDR full white isn't very bright.  I want the ability to have brightness levels that cause bloom and have a significant effect on Global Illumination (currently GI is only noticeably affecting objects fairly close to the texture).


Recent versions of Photoshop can handle 32-bit per channel floating point images.

 

Good to know!

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I think we're on different pages here. I'm not going from source photos like a skybox, I want to make an HDR texture from scratch using drawing tools, e.g. circles, boxes, blur, etc. 

I thought so, I think you mean High-Depth images not High-Dynamic-Range.

Maybe that's something engine specific. I'm already using full colour emission maps in Unity. The problem is that using SDR full white isn't very bright.  I want the ability to have brightness levels that cause bloom and have a significant effect on Global Illumination (currently GI is only noticeably affecting objects fairly close to the texture).

I forgot Unity is so wasteful with it's textures. <_<

 

Using a higher bit rate isn't going to increase the brightness of the emissive material.

The shader reads the texture as Black= 0 no emissive and white as 1 full emissive. The color depth only decides the amount of steps between 0 - 1, with 8 bit allowing for 255 steps and 32 bit 16,777,215 white is still max (255,255,255) or (16,777,215, 16,777,215, 16,777,215) both = 1.

This is the same way pixels on your screen work, they can't go over full on.

 

The way a game would make the light brighter is by making every thing else darker, and with over exposure (HDR). Unity will do this for you if you use a normal emissive texture and adjust the value next to the emissive to more than 1.

There is no point in using HDR textures, in fact Unity expects normal textures.

 

 

HDR is not a texture type it's a composition effect, Unity will do the composition for you. :wink: 

Edited by Scouting Ninja

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I'm surprised if Unity doesn't support floating-point textures, as Unreal certainly does. Then again, some mobile devices and old GPUs may not have support for them, so Unity may simply cater for a lower common denominator.

With floating-point images, it is perfectly viable (and common) to store values beyond 0...1 range; for example, the immediate vicinity of the sun is physically several orders of magnitude brighter than the rest of the sky, and the image could still preserve the brightness dynamic (as in high dynamic range) of both the sky and the sun so as to preserve the details for every area of the image without "burning through".

HDR is very useful as input for physically-based lighting. Though the results need to be tone-mapped for the display device (scaling the values to a practical displayable range), HDR often enables very realistic lighting that works with both dark and bright scenes.

Edited by Nik02

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