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View Full Version : STALINGRAD-Vfx Coverage article from cgsociety



prometheus
12-27-2013, 06:56 AM
A movie about the battle in stalingrad, of course it canīt be without explosions,debris etc..hereīs a nice coverage about what the vfx challenges was, and how they approached and solved, It can be found in this
article...
http://www.cgsociety.org/index.php/CGSFeatures/CGSFeatureSpecial/stalingrad

I havenīt seen the movie though...so vfx being good? I donīt know.

Michael

3DGFXStudios
12-27-2013, 07:08 AM
Holy smokes! The fire and smoke animations look really cool. I hope TFD shading will soon meet this kind of quality.

prometheus
12-27-2013, 07:35 AM
Holy smokes! The fire and smoke animations look really cool. I hope TFD shading will soon meet this kind of quality.

Iīm not sure, but I think it might be already, depends very much on how far you as an artist knows how to tweak TFD shading and also being able to convey that knowledge to match a lot of real reference materials
to get the desired looks, and that takes resource material and time and a good eye for it, so I donīt believe thereīs something extra in those fluid shaders compared to what you might be able to pull of with turbulenceFD really.

Notable and to be aware of, the displacement noise to add in detail in simulations increased rendertimes from minutes to hours, that is a problem faced in their fluid solution and it is a problem with most fluid solutions I guess, as in turbulenceFD too.
Keep in mind that they did a lot of research from world war photage on how earth and dust clouds are whipped up and how it behaves in the air and with gravity and how it dissolves etc.
And I think it was mixture too between sandbags filled with dirt,dust,chips etc and exploding that, but not sure..it might have been only for reference, not sure it was actually used as live plates due to stereographic issues.

I saw a short trailer clip where a building exploded, and I could instantly tell there was a type of render quality to it, as opposed to real pyrodynamics, and I think they comprimized there between realism and speed needed for rendering, that is I donīt think they used a proper opacity/shadow shading or a good illumination scattering mode for that particular explosion...that is however what you often see due to the enourmous time of rendering it would otherwise require I think.

You can see the same "style" almost in the lightwave winter session presentation somewhere, where we see a fluid explosion (turbulenceFD) showcasing a non full illumination quality in the renderer, and it isnīt even close to the quality you would see in the stalingrad clip.

Employ the proper illumination methods, tweak the shader to the fullest and I am convinced turbulence can produce equally good looking shading...but it takes an experienced user of that fluid solution and also one that has a good eye to match it towards true life photage, heck not even in avatar could they pull the fullest realism out of the fire and fluid explosions...im sure there are better samples out there.

Michael

50one
12-27-2013, 07:54 AM
It really shows the power of Houdini.

prometheus
12-27-2013, 07:55 AM
actually..I missed the reel...
http://www.youtube.com/watch?v=BGA73iBDLMA#t=469

as with other art stuff, when you see the canvas with a multitude of layers being nicely added to the scene, it looks awesome, so here we got a multitude of huge complex simulations taking place then layered back on to the
scene.

also..many firesequences has this fluid displacement adapted rather than just a very high res simulations, so it probably made the simulation process easier and faster to complete, and then adding fluid displacement mapping, when looking
carefully you can indeed tell it isnīt truly naturalistic in appearance, since it only distorts the shading to give that extra fire detail, but it is close enough I suppose.
Then apart from the fluid shader, you have the debris and particle works driving the fluids, that is another level important for the realism, it need to explode right with correct time and speed/velocity and also dampen correctly as debri pieces does in the real world, pressure forces etc..

Michael

prometheus
12-27-2013, 12:13 PM
It really shows the power of Houdini.

Indeed powerful, I wish houdini could start up faster (takes ages) and be easier to use and start the renderer without taking ages to do so, Lightwave flies in rocket speed around houdini and compared to how fast you get up and running with houdini in terms of starting the app, and starting the renderer...im really frustrated about how long it takes for both mantra types to simply just start itīs dialog process for the rendering.

TurbulenceFD is actually not bad in speed either and the feedback you get from it, in terms of adusting parameters shadings etc...
houdini is probably a beast in other ways though, with the level of control on everything, with dynamics, how to handle large scale simulations etc and to drive the simulations from other dynamic forces or items.

the feedback overview in opengl is a plus for houdini as up today I think, that is for turbulence we can only see either fire or the smoke shader, but not at the same time, and the smoke shader isnīt represented well to match what is actually rendered, in houdini you can see both fire and smoke in openGL...sure VPR in lightwave helps, but it doesnīt provide realtime feedback when playing the sim.
Houdini got itīs nice cloudFX tools and openGL to showcase that, we donīt have any voxel openGL presentation anywere near that.

large scale simulation handling and fluid displacement mapping which can be rendered much much faster in VPR or within itīs own previewer would be sweet, maybe GPU rendering of it could be a future road to look at, that
is if you have invested in a graphics card or two that could take use of it, for example certain nvidia cuda cards.

I have yet to try the interactive tweak fluids in realtime feature in turbulenceFD since my nvidia drivers havenīt been updated yet.


Michael

50one
12-27-2013, 12:38 PM
Indeed powerful, I wish houdini could start up faster (takes ages) and be easier to use and start the renderer without taking ages to do so, Lightwave flies in rocket speed around houdini and compared to how fast you get up and running with houdini in terms of starting the app, and starting the renderer...im really frustrated about how long it takes for both mantra types to simply just start itīs dialog process for the rendering.

TurbulenceFD is actually not bad in speed either and the feedback you get from it, in terms of adusting parameters shadings etc...
houdini is probably a beast in other ways though, with the level of control on everything, with dynamics, how to handle large scale simulations etc and to drive the simulations from other dynamic forces or items.

the feedback overview in opengl is a plus for houdini as up today I think, that is for turbulence we can only see either fire or the smoke shader, but not at the same time, and the smoke shader isnīt represented well to match what is actually rendered, in houdini you can see both fire and smoke in openGL...sure VPR in lightwave helps, but it doesnīt provide realtime feedback when playing the sim.
Houdini got itīs nice cloudFX tools and openGL to showcase that, we donīt have any voxel openGL presentation anywere near that.

large scale simulation handling and fluid displacement mapping which can be rendered much much faster in VPR or within itīs own previewer would be sweet, maybe GPU rendering of it could be a future road to look at, that
is if you have invested in a graphics card or two that could take use of it, for example certain nvidia cuda cards.

I have yet to try the interactive tweak fluids in realtime feature in turbulenceFD since my nvidia drivers havenīt been updated yet.


Michael


Since I installed 3dsmax and not so long ago Houdini apprentice on my SSD I cannot complain on start-up time, of course Modo, Blender and LW are champions in this regard, but they're not as feature complete.

prometheus
12-27-2013, 12:49 PM
Since I installed 3dsmax and not so long ago Houdini apprentice on my SSD I cannot complain on start-up time, of course Modo, Blender and LW are champions in this regard, but they're not as feature complete.

guess I have tot get my a SSD storage then:)
until then ...I have to complain.
But what is the actual time for houdini until it starts its renderer for a simple thing or cloudfx, I mean...I have to wait many many seconds for houdini to even start the render process, where in lightwave it starts immediatly.

Michael

50one
12-27-2013, 01:10 PM
guess I have tot get my a SSD storage then:)
until then ...I have to complain.
But what is the actual time for houdini until it starts its renderer for a simple thing or cloudfx, I mean...I have to wait many many seconds for houdini to even start the render process, where in lightwave it starts immediatly.

Michael

Ssd's are amazing, got one running my win7 and other one with apps only Nd this thing just fly, even tho is fairly dated. I can only tell by the sample scenes I opened and it takes usually few seconds, depends on the tree complexity.

3DGFXStudios
12-27-2013, 01:14 PM
Iīm not sure, but I think it might be already, depends very much on how far you as an artist knows how to tweak TFD shading and also being able to convey that knowledge to match a lot of real reference materials
to get the desired looks, and that takes resource material and time and a good eye for it, so I donīt believe thereīs something extra in those fluid shaders compared to what you might be able to pull of with turbulenceFD really.

Notable and to be aware of, the displacement noise to add in detail in simulations increased rendertimes from minutes to hours, that is a problem faced in their fluid solution and it is a problem with most fluid solutions I guess, as in turbulenceFD too.
Keep in mind that they did a lot of research from world war photage on how earth and dust clouds are whipped up and how it behaves in the air and with gravity and how it dissolves etc.
And I think it was mixture too between sandbags filled with dirt,dust,chips etc and exploding that, but not sure..it might have been only for reference, not sure it was actually used as live plates due to stereographic issues.

I saw a short trailer clip where a building exploded, and I could instantly tell there was a type of render quality to it, as opposed to real pyrodynamics, and I think they comprimized there between realism and speed needed for rendering, that is I donīt think they used a proper opacity/shadow shading or a good illumination scattering mode for that particular explosion...that is however what you often see due to the enourmous time of rendering it would otherwise require I think.

You can see the same "style" almost in the lightwave winter session presentation somewhere, where we see a fluid explosion (turbulenceFD) showcasing a non full illumination quality in the renderer, and it isnīt even close to the quality you would see in the stalingrad clip.

Employ the proper illumination methods, tweak the shader to the fullest and I am convinced turbulence can produce equally good looking shading...but it takes an experienced user of that fluid solution and also one that has a good eye to match it towards true life photage, heck not even in avatar could they pull the fullest realism out of the fire and fluid explosions...im sure there are better samples out there.

Michael

Currently TFD doesn't support smoke to be illuminated by HDRI. Don't get confused with the radiosity rays the fire emits. I doesn't receive LW radiosity rays. There are some tricks like using a DPdome light with an image to illuminate the smoke with an HDRI but that increases the render time a lot. Or using Lightbitch from hdrlabs. So TFD is certainly not as complete as the Houdini smoke simulator. There isn't a fast way to shade self illuminating smoke. The controls for that are very limited. There is no way you can get this look in TFD: http://www.nasa.gov/images/content/739339main_Space_Shuttle_Challenger_04-04-1983.jpg
And there are more problems, some bigger than the other but you can't for example mix different colors of smoke in TFD. I don't want to brag but I've a fairly good understanding how TFD works and I think it's awesome :D

prometheus
12-27-2013, 02:25 PM
Currently TFD doesn't support smoke to be illuminated by HDRI. Don't get confused with the radiosity rays the fire emits. I doesn't receive LW radiosity rays. There are some tricks like using a DPdome light with an image to illuminate the smoke with an HDRI but that increases the render time a lot. Or using Lightbitch from hdrlabs. So TFD is certainly not as complete as the Houdini smoke simulator. There isn't a fast way to shade self illuminating smoke. The controls for that are very limited. There is no way you can get this look in TFD: http://www.nasa.gov/images/content/739339main_Space_Shuttle_Challenger_04-04-1983.jpg
And there are more problems, some bigger than the other but you can't for example mix different colors of smoke in TFD. I don't want to brag but I've a fairly good understanding how TFD works and I think it's awesome :D

That might indeed be the case, Im not familiar with hdr illlumination of fluids in houdini, that I need to read up on.
however, I donīt think I can see a distinctive showcase of hdr illumination in the smoke effects in the Stalingrad vfx clips, thus I think the fluid shading shouldnīt be that difficult to match in turbulenceFD fluids.
So we simply donīt know if they at all used hdr lighting for the smoke at all.

The image sample you showned is a real photage I guess:) I would like to see a houdini fluid shot, looking like that, and I personally donīt think it might be hdr lighting that would be the thing for ultimate realism here, what would
be daunting is the amount of resolution in order to convey the smoke billowing detail in there, donīt think subgrid detail or velocity displacement will get you there.
you could probably perform a smaller sim of it, but at that scale....it will be daunting I reckon.

mixing different colors of smoke, sure a limitation too, but I really donīt see any distinct color mixing in the vfx smoke shotīs either in stalingrad reels, and a lot becomes color graded.
So based on the general shading look from the vfx we are talking about and from what you said you wished could be acheived in turbulenceFD, I think it wouldīt be that impossible to match it, if you start to pull up
other limitations and other real life photage, thatīs another discussion.

Edited...a second look, a global illumination method with hdr, or other soft shadow illumination might indeed enhance the smoke look of shuttle launch to a different level of realism, I havenīt gone there
to set such huge simulation up and with all that lighting going on so Im just speculatin, though I donīt think we can see anything of that level in the illumination of the smoke in stalingrad samples.

Michael