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Terrain Mapping
Terrain Mapping II
RenderCow
Indoor Radiosity
altTerrainBuilder
Creating a Gradient Material
Making a Tire- Part I: Text Model
Making a Tire- Part II: Textures
Mapping Notes
Adding DOF in Photoshop
Understanding Smoothing in Vue
VueTools
Fog and Haze
This is a tutorial which will help explain the obtuse relationship between fog and haze in Vue. Unlike most 3D applications, fog and haze do not function in a normal way, and it's sometimes difficult to find the correct 'settings.' Furthermore, the same named settings provide very different functions depending upon which atmosphere mode you are working in.
Hopefully, this tutorial will help you better understand these relationships.
Terrain Mapping
Terrain Mapping II
RenderCow
Indoor Radiosity
altTerrainBuilder
Creating a Gradient Material
Making a Tire- Part I: Text Model
Making a Tire- Part II: Textures
Mapping Notes
Adding DOF in Photoshop
Understanding Smoothing in Vue
VueTools
Fog and Haze
This is a tutorial which will help explain the obtuse relationship between fog and haze in Vue. Unlike most 3D applications, fog and haze do not function in a normal way, and it's sometimes difficult to find the correct 'settings.' Furthermore, the same named settings provide very different functions depending upon which atmosphere mode you are working in.
Hopefully, this tutorial will help you better understand these relationships.
Understanding Fog and Haze
Created by Chipp Walters of Altuit, Inc.
Created by Chipp Walters of Altuit, Inc.
The Setup
A blank scene was created and multiple objects added going towards the horizon at a regular distance. The following Light Settings from the Atmoshphereeditor were used to render the scene.
The goal was to render enough different Fog and Haze settings, for both Standard and Volumetric atmosphere models.
I used a black sky for the Standard atmosphere. It turns out it doesn't matter what color sky you use for Volumetric atmospheres.
The hope was I could finally discern what the various relationships were between the different settings for Fog and Haze. I think I was successful, but you can be the judge.
A blank scene was created and multiple objects added going towards the horizon at a regular distance. The following Light Settings from the Atmoshphereeditor were used to render the scene.The goal was to render enough different Fog and Haze settings, for both Standard and Volumetric atmosphere models.
I used a black sky for the Standard atmosphere. It turns out it doesn't matter what color sky you use for Volumetric atmospheres.
The hope was I could finally discern what the various relationships were between the different settings for Fog and Haze. I think I was successful, but you can be the judge.
Standard Atmosphere Settings
Here's a picture of the basic Standard atmosphere settings.
I used different settings for all the controls except:
...at low altitudes and ...at high altitudes.
I expect we all know what they mean. The color for fog and haze are the default colors present when you load No Atmosphere from the Atmosphere library.
Here's a picture of the basic Standard atmosphere settings.I used different settings for all the controls except:
...at low altitudes and ...at high altitudes.
I expect we all know what they mean. The color for fog and haze are the default colors present when you load No Atmosphere from the Atmosphere library.
Basic Fog
Here you see the basic Fog tests. The farthest left is no Fog (or Haze) at all. All of these tests assume falloff is 0. The renderings show Fog settings of 200,400,800.
So, Fog does not affect the sky in Standard mode. It only affects objects. And when Falloff is not present it affects objects equally top to bottom.
Here you see the basic Fog tests. The farthest left is no Fog (or Haze) at all. All of these tests assume falloff is 0. The renderings show Fog settings of 200,400,800.So, Fog does not affect the sky in Standard mode. It only affects objects. And when Falloff is not present it affects objects equally top to bottom.
Fog with Falloff
The leftmost image shows the effect of the Falloff setting even though the Fog Density is 0. The third image shows the exact same Falloff settings (Falloff of 40 with Altitude of 60) with a Density of 400.
The second image shows fog at the same Density and Falloff as the 3rd image, but with a different Altitude. The last image demonstrates Fog settings do not affect the sky color whatsoever.
The leftmost image shows the effect of the Falloff setting even though the Fog Density is 0. The third image shows the exact same Falloff settings (Falloff of 40 with Altitude of 60) with a Density of 400.The second image shows fog at the same Density and Falloff as the 3rd image, but with a different Altitude. The last image demonstrates Fog settings do not affect the sky color whatsoever.
So, here's what I've figured out about Fog Falloff. The Falloff setting is completely separate from the Density setting, in other words one doesn't affect the other.
Think of Density as how far away from the camera does the fog start. And think of Falloff as how dense is the fog from the ground as it comes up? And think of Altitude as how high the fog comes up.
It's confusing based upon what you see. In all of these images, the Density of the fog is 0. In otherwords, the fog is the same opaqueness from the camera to the horizon. The first picture looks like fog is in the distance, and fades out the closer it gets to you. But, in fact the Density is 0, and the Falloff is a small 20. That means the fog is not very dense near the ground, but as we view closer to the horizon, even a small density of only 20 adds up to create an opaque fog over the long distance.
Now look at the second image, it also appears to have the same effect— that is the fog recedes. But this time the Falloff is set to 100, which is the most opaque setting. Even so, because the Altitude is so low (10) it doesn't have enough thickness to be opaque close to the camera.
The third and fourth images perhaps best demonstrate the effect of Falloff. The third image shows Falloff at 100 which is the highest opacity. As you see, the fog rises to the bottom of the window. The forth image has a Falloff of only 50, and while the Fog Altitude is the same as the third image, the opaqueness (Falloff) is much less so it doesn't quite look like it's at the same altitude.
If you're trying to create a 'foggy floor', then you should raise the Falloff to a high number.
Haze
Haze Density behaves EXACTLY like Fog Density when in the Standard atmosphere setting! You can of course change the color. As you can see in the images here, the more haze which is added, the closer it comes to the camera.
Haze Density behaves EXACTLY like Fog Density when in the Standard atmosphere setting! You can of course change the color. As you can see in the images here, the more haze which is added, the closer it comes to the camera.
Modifying the Sky Fog in Standard Atmosphere
Using the Fog in the sky setting in teh Sky tab for the Standard Model, you can adjust how much of the Fog color affects the sky at the horizon.
This is a VERY POWERFUL feature of Standard Atmosphere's and can create very realistic scenes which render super fast.
By maximizing the Thickness to 100% and using the Max. altitude slider, you can create an image like this one, where there is no discernable horizon. Very powerful indeed.
Using the Fog in the sky setting in teh Sky tab for the Standard Model, you can adjust how much of the Fog color affects the sky at the horizon. This is a VERY POWERFUL feature of Standard Atmosphere's and can create very realistic scenes which render super fast.
By maximizing the Thickness to 100% and using the Max. altitude slider, you can create an image like this one, where there is no discernable horizon. Very powerful indeed.
Standard atmosphere conclusion
Here are a few interesting observations regarding the Standard atmosphere.
1. What most 3D packages think of as fog, is actually represented by the Fog Falloff control, not the Fog Density control.
2. Fog Density and Haze Density are in fact basically the same, just with different colors.
3. You need to use the Sky tab in the Standard Atmosphere in order to affect the sky with the fog settings. This is a very important part of setting up your atmosphere and can lead to super quality renderings and lower rendering times.
4. Fog Density and Fog Falloff are two different controls and have no affect on each other.
1. What most 3D packages think of as fog, is actually represented by the Fog Falloff control, not the Fog Density control.
2. Fog Density and Haze Density are in fact basically the same, just with different colors.
3. You need to use the Sky tab in the Standard Atmosphere in order to affect the sky with the fog settings. This is a very important part of setting up your atmosphere and can lead to super quality renderings and lower rendering times.
4. Fog Density and Fog Falloff are two different controls and have no affect on each other.
Volumetric Atmosphere Settings
Here are the Volumetric atmosphere settings. I didn't concern myself with testing either the Quality boost or volumetric sunlight settings. This is because they didn't seem to alter the findings of this experiment much at all.
The first thing you discover about the Volumetric atmosphere, is that the sky color is determined wholly by the settings in this panel. Also, using a Volumetric atmosphere is an effective way to have Haze and Fog settings affect your sky.
Here are the Volumetric atmosphere settings. I didn't concern myself with testing either the Quality boost or volumetric sunlight settings. This is because they didn't seem to alter the findings of this experiment much at all.The first thing you discover about the Volumetric atmosphere, is that the sky color is determined wholly by the settings in this panel. Also, using a Volumetric atmosphere is an effective way to have Haze and Fog settings affect your sky.
Volumetric Haze
The Haze Color determines the main hue (color) of the sky. The Haze Density determines the value (light to dark) of the sky.
In all of these images, the Falloff setting is 0. The far left image shows the scene with 0 density and the sky has a value of 0 (completely dark). At settings of 100,200 and 300, you see the value of the sky get lighter with respect to the contribution of the density.
The Haze Color determines the main hue (color) of the sky. The Haze Density determines the value (light to dark) of the sky.In all of these images, the Falloff setting is 0. The far left image shows the scene with 0 density and the sky has a value of 0 (completely dark). At settings of 100,200 and 300, you see the value of the sky get lighter with respect to the contribution of the density.
Volumetric Haze Falloff
The Haze Falloff setting is what creates the sky ramp effect. As shown in these images, the higher the Falloff setting, the greater the value range in the ramp. The horizon color is set by the Density slider, while the zenith (or top of the picture) color is set by the contribution of the Falloff, combined with the native Haze Color at a low value.
So, basically, you can adjust the horizon color lighter by adjusting the Density higher, and strengthen the ramp effect by adjusting the Falloff higher.
The Haze Falloff setting is what creates the sky ramp effect. As shown in these images, the higher the Falloff setting, the greater the value range in the ramp. The horizon color is set by the Density slider, while the zenith (or top of the picture) color is set by the contribution of the Falloff, combined with the native Haze Color at a low value.So, basically, you can adjust the horizon color lighter by adjusting the Density higher, and strengthen the ramp effect by adjusting the Falloff higher.
Haze Glow
As these pictures show, the Glow intensity setting has little effect on the Haze settings.
As these pictures show, the Glow intensity setting has little effect on the Haze settings.
Volumetric Fog
Volumetric Fog is different from Standard Fog.
All the images shown here have Haze Density 150, and Haze Falloff 50.
The image on the left has a Fog Density of 0. The other images show Fog Densities of 50,150 and 650. Much like the Standard Fog, Volumetric Fog affects objects from the camera to the horizon, but with Volumetric Fog the sky is affected as well.
Volumetric Fog is different from Standard Fog.All the images shown here have Haze Density 150, and Haze Falloff 50.
The image on the left has a Fog Density of 0. The other images show Fog Densities of 50,150 and 650. Much like the Standard Fog, Volumetric Fog affects objects from the camera to the horizon, but with Volumetric Fog the sky is affected as well.
Volumetric Fog Falloff
Volumetric Fog Falloff is altogether different from Standard Fog Falloff.
Unlike the Falloff control in the Standard atmosphere which has no relation to the Standard Fog Density control, the Volumetic Fog Falloff works directly with the Volumetric Fog Density control. In fact, if the Fog Density is set to 0, then the Fog Falloff will have no effect.
There is no notion of verticality with Volumetric Fog Falloff. In otherwords, you can't create a fog which hugs the ground using a Volumetric atmosphere.
The Falloff control manages how quickly the fog effect diminishes from the horizon to the camera. The greater the number, the less the effect is closer to the camera. So, if you want objects, such as mountains, to fade, you can use a high setting for the Fog Falloff. If you are creating a foggy night scene, then you would use a low setting.
Volumetric Fog Falloff is altogether different from Standard Fog Falloff. Unlike the Falloff control in the Standard atmosphere which has no relation to the Standard Fog Density control, the Volumetic Fog Falloff works directly with the Volumetric Fog Density control. In fact, if the Fog Density is set to 0, then the Fog Falloff will have no effect.
There is no notion of verticality with Volumetric Fog Falloff. In otherwords, you can't create a fog which hugs the ground using a Volumetric atmosphere.
The Falloff control manages how quickly the fog effect diminishes from the horizon to the camera. The greater the number, the less the effect is closer to the camera. So, if you want objects, such as mountains, to fade, you can use a high setting for the Fog Falloff. If you are creating a foggy night scene, then you would use a low setting.
Fog Glow
While the Glow intensity control has no effect on Haze settings, it does on Fog settings. It will place a glow around the light based upon the slider setting. Larger numbers create a larger glow, smaller numbers create less of a glow.
While the Glow intensity control has no effect on Haze settings, it does on Fog settings. It will place a glow around the light based upon the slider setting. Larger numbers create a larger glow, smaller numbers create less of a glow.
Volumetric Atmosphere Conclusion
While it does take a bit longer to render, Volumetric atmospheres are better in dealing with both Fog and Haze in expected ways. Unfortunately, you can't create a ground fog effect in Volumetric mode.
If you're creating a scene, which has distant mountains or a view of the horizon over the ocean, you probably should consider using a Volumetric atmosphere.
Some important things to remember:
1) The Haze controls the color of the sky. So start off by turing off all fog and set your sky color. Use the Haze Density control to set the horizon color and the Haze Falloff control to set the sky ramp effect.
2) For clear days , use low Fog Density and high Fog Falloff. For overcast days, use the reverse.
3) You cannot use Volumetric fog to create a ground cover fog effect.
4) Unlike in the Standard atmosphere settings, Volumetric Fog Density and Fog Falloff are related.
If you're creating a scene, which has distant mountains or a view of the horizon over the ocean, you probably should consider using a Volumetric atmosphere.
Some important things to remember:
1) The Haze controls the color of the sky. So start off by turing off all fog and set your sky color. Use the Haze Density control to set the horizon color and the Haze Falloff control to set the sky ramp effect.
2) For clear days , use low Fog Density and high Fog Falloff. For overcast days, use the reverse.
3) You cannot use Volumetric fog to create a ground cover fog effect.
4) Unlike in the Standard atmosphere settings, Volumetric Fog Density and Fog Falloff are related.
This tutorial as PDF
Here's this tutorial in PDF format
Here's this tutorial in PDF format
