Parallax, is it worth it over specular ?
by Andy Wright · in Torque 3D Professional · 08/14/2013 (6:34 am) · 28 replies
Ok, I've always been a fan of parallax on terrain materials but I've been making textures from a new source, and playing around with what I used to do for parallax maps, and an old idea I had before that let specular work on small areas of terrain by overlaying a transparent decal with specular on, then testing some textures on a shape too, to see how they look.
I've come to the conclusion that while parallax is nice and all for that extra 'geometry' detail when done right that makes it pop out at you, its visual gains arent as much as what specular would give to terrains as to the real 'feel' of the material... mostly due to what a good normal map gives with the shadows having parallax on top is just a fancy extra boost for the normals, yet specular would add alot more visually to the materials real feel/look.
with that recent thread about the blending or materials and using opacity masks in one of the alpha channels, im starting to personally feel that to get T3D's large terrains looking top notch, it might be worth considering removing the parallax pass all together and replace with it with specular, as like for like comparisons imo you gain more from the specular... add along side that an opacity mask to control the blending of materials, and i think we'd be about there with terrain materials...
I've come to the conclusion that while parallax is nice and all for that extra 'geometry' detail when done right that makes it pop out at you, its visual gains arent as much as what specular would give to terrains as to the real 'feel' of the material... mostly due to what a good normal map gives with the shadows having parallax on top is just a fancy extra boost for the normals, yet specular would add alot more visually to the materials real feel/look.
with that recent thread about the blending or materials and using opacity masks in one of the alpha channels, im starting to personally feel that to get T3D's large terrains looking top notch, it might be worth considering removing the parallax pass all together and replace with it with specular, as like for like comparisons imo you gain more from the specular... add along side that an opacity mask to control the blending of materials, and i think we'd be about there with terrain materials...
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#2
08/14/2013 (6:47 am)
Instead of removing it completely, make it optional? A setting that turns it off or on. Imo it would be pointless to actually remove a feature thats already implemented when you can just turn it off.
#3
08/14/2013 (6:48 am)
Depends on the art style for what youre trying to achieve, youre right though, even normals arent always required, but personally it can feel a bit cartoony and too flat without normals for the way i like.
#4
08/14/2013 (6:49 am)
well yes, there is always that possibility, but people will just have to understand that theres a point where youre doing far too many draw calls on a terrain that really starts to punish framerates when there are too many bells and whistles being added to it...
#5
The standard should IMO be having one of them turned off and maybe there should a be a warning about having both turned on, but having one or the other or both turned one should be optional.
08/14/2013 (7:42 am)
@Andy imo that should really be up to the game dev himself. Especially because that, a game dev with respect for himself would know to be careful with terrain-wide shaders.The standard should IMO be having one of them turned off and maybe there should a be a warning about having both turned on, but having one or the other or both turned one should be optional.
#6
edit: Specular should be parrallax - I just rolled out of bed, need more tea for brain to work :P
08/14/2013 (7:55 am)
Specular is disabled in the options when lower than normal shader quality - and hell I modded that so it only uses parallax on high.edit: Specular should be parrallax - I just rolled out of bed, need more tea for brain to work :P
#7
Originally, specular was skipped because doing both a parallax pass and a specular pass was a bit too much so they decided to say it's either parallax or specular on terrain materials, and decided for parallax.
08/14/2013 (8:01 am)
@Steve I think it's about parallax / specular on terrain materials and not materials in general.Originally, specular was skipped because doing both a parallax pass and a specular pass was a bit too much so they decided to say it's either parallax or specular on terrain materials, and decided for parallax.
#8
let me use words right
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Parallax is disabled in the options when lower than normal shader quality - and hell I modded that so it only uses parallax on high.
08/14/2013 (8:23 am)
Derp ---let me use words right
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Parallax is disabled in the options when lower than normal shader quality - and hell I modded that so it only uses parallax on high.
#9
08/14/2013 (8:48 am)
Oh so turning of parallax is already implemented. We can just implement specular then and turn of the one you find is unnecessary.
#10
Having both would be nice, with a warning about memory usage etc as you suggest when selecting which one you use
08/14/2013 (10:07 am)
Yeah i remember tom spillman talking about it, and they opted for parallax over specular when initially making the new terrain system. Having both would be nice, with a warning about memory usage etc as you suggest when selecting which one you use
#11
08/14/2013 (1:26 pm)
Or make it so you can select one or the other in the terrain material - "This here texture map slot is for specular/parallax, please use the correct image and pick one, you goob."
#12
08/14/2013 (1:39 pm)
Currently there is no slot for parallax though, since its just the alpha channel of the normal map.I would like to see the alpha map blending.IMHO the more options the better. I'd be fine with specular and parallax enabled, my video card has over 3gb ram...
#13
08/14/2013 (1:40 pm)
yeah but having a mix of materials on a terrain where you have some with spex and some with parallax would still mean more passes, i think if it was an either or situation, specular wins it for the overall effect... yes, its nice to give some rocks a bit of parallax, but its not needed majority of the time at all, the gain you get isnt worth the cost, yet specular has a much broader appeal... 
#14
I like the idea of both but I don't think parallax should be removed.
It really should be at the discretion of the dev.
Btw do you have any screenshot showing spec over parallax?
I personally like parallax but if spec is better performance wise then maybe
I can start rethinking level designs.
08/14/2013 (2:28 pm)
Andy I like the idea of both but I don't think parallax should be removed.
It really should be at the discretion of the dev.
Btw do you have any screenshot showing spec over parallax?
I personally like parallax but if spec is better performance wise then maybe
I can start rethinking level designs.
#15
08/14/2013 (3:47 pm)
I dont Kory, not on a terrain anyway, the way it should be calculated, all I have done is put a transparent decal over the terrain and scaled it up a bit, that picks up the normal map from the terrain and a generic specular from that. Making the decal huge though is an absolute resource hog, dont know why it grinds me to a halt from certain angles, but it looks good even with just a mask like that, it would/should, in theory, look the same as if you used the texture on a dts with specular applied to it..
#16
Specular maps usually don't need to be as big as the diffuse or normal map. Half the size is often enough to maintain the quality. I think you need to do some testing first which one is more costly:
Extra layer with 4 bit specular map, half (example) the size of the diffuse map
or
Adding a full size alpha channel for specular , forcing 4 bit maps to be 8 bit
08/14/2013 (6:24 pm)
I'm not using parallax on terrain but removing it will make it not compatible for existing terrain materials that use it.Specular maps usually don't need to be as big as the diffuse or normal map. Half the size is often enough to maintain the quality. I think you need to do some testing first which one is more costly:
Extra layer with 4 bit specular map, half (example) the size of the diffuse map
or
Adding a full size alpha channel for specular , forcing 4 bit maps to be 8 bit
#17
08/14/2013 (9:22 pm)
I think we can probably agree removing parallax is a bad idea. Seems like the only option is to let designers use the parallax map (alpha channel of normal map) for specular instead. So you can choose - a terrain either has parallax or specular.
#18
08/14/2013 (9:44 pm)
Could it be done per layer/material instead of for the whole terrain? 
#19
When I added the macro layer, it was pretty much a challenge to myself to open up the engine and see if my hunch was right - that it would be useful and doable. I copy and pasted code, slightly renaming functions, and duplicated things in the engine. It was quick and dirty, but it worked.
I think just doing that again for another layer that will end up having a single line or two of shader code different in the end would be ugly. Richard had it right in post #11, people should select their texture, select how it will be used, and then fill in the needed variables. Making the explicit bits of the interface general purpose should happen internally too, and that's where I get stuck. How the engine loads terrain materials and makes shaders from them kinda needs to be re-thunk, and how the macro stuff was implemented makes it obvious.
But yeah, it could be done without messing up current materials or needing to mess with the parallax at all. People need to show restraint with this stuff. I'd use a detail + specular with no normal for snow or wet sand.
08/16/2013 (12:08 pm)
Hmm. Yeah, I see how to add a specular layer. But I'm not certain how to do it the right way.When I added the macro layer, it was pretty much a challenge to myself to open up the engine and see if my hunch was right - that it would be useful and doable. I copy and pasted code, slightly renaming functions, and duplicated things in the engine. It was quick and dirty, but it worked.
I think just doing that again for another layer that will end up having a single line or two of shader code different in the end would be ugly. Richard had it right in post #11, people should select their texture, select how it will be used, and then fill in the needed variables. Making the explicit bits of the interface general purpose should happen internally too, and that's where I get stuck. How the engine loads terrain materials and makes shaders from them kinda needs to be re-thunk, and how the macro stuff was implemented makes it obvious.
But yeah, it could be done without messing up current materials or needing to mess with the parallax at all. People need to show restraint with this stuff. I'd use a detail + specular with no normal for snow or wet sand.
#20
08/17/2013 (8:24 pm)
I'm getting kind of confused about choosing one over the other. Specular mapping controls the glossiness of the surface and parallax controls the depth warping of the surface creating artificial depth around cracks and such. So why would one be chosen over the other wouldn't you just want use both? 
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