This is a work-in-progress inspired by a photo I took of my grandson 
chasing soap bubbles in his yard.  As usual, it was supposed to be a 
brief doodle, but has morphed beyond that.  I have started adding other 
things that "float" in various ways to model in the scene as well.


-- 
-- Chris R

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"RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
> This is a work-in-progress inspired by a photo I took of my grandson
> chasing soap bubbles in his yard.  As usual, it was supposed to be a
> brief doodle, but has morphed beyond that.  I have started adding other
> things that "float" in various ways to model in the scene as well.

Are those floating objects intended to be bubbles?  They look like solid water
droplets.  Hollow bubbles do not invert the scene behind them.

The cracks in the pink granite blocks are conspicuously regular, but I'm sure
you already have plans for those.

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On 4/13/2024 2:55 PM, Cousin Ricky wrote:
> "RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
>> This is a work-in-progress inspired by a photo I took of my grandson
>> chasing soap bubbles in his yard.  As usual, it was supposed to be a
>> brief doodle, but has morphed beyond that.  I have started adding other
>> things that "float" in various ways to model in the scene as well.
> 
> Are those floating objects intended to be bubbles?  They look like solid water
> droplets.  Hollow bubbles do not invert the scene behind them.
> 
> The cracks in the pink granite blocks are conspicuously regular, but I'm sure
> you already have plans for those.
> 
> 
> 
Yes, the are supposed to be bubbles.  I'm not sure what I'm doing wrong 
yet, but I have noticed that effect.  They are isosurface shells with 
very thin walls.  The material has an ior of 1.33, which is wrong and is 
probably causing the issue.  I guess a soap bubble has an ior pretty 
close to 1, so I'll have to play with that.  I think when I was trying 
to get the irrid right I pushed the ior back up, but got that side-effect.

The balloon isn't quite right either.  It's too glossy so it looks more 
like glass.

I think the cracks need to line up with the cracks in the foundation as 
well.  More things to play with.
-- 
-- Chris R

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Le 2024-04-13 à 15:07, RATH, CHRISTOPHER A a écrit :
> On 4/13/2024 2:55 PM, Cousin Ricky wrote:
>> "RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
>>> This is a work-in-progress inspired by a photo I took of my grandson
>>> chasing soap bubbles in his yard.  As usual, it was supposed to be a
>>> brief doodle, but has morphed beyond that.  I have started adding other
>>> things that "float" in various ways to model in the scene as well.
>>
>> Are those floating objects intended to be bubbles?  They look like 
>> solid water
>> droplets.  Hollow bubbles do not invert the scene behind them.
>>
>> The cracks in the pink granite blocks are conspicuously regular, but 
>> I'm sure
>> you already have plans for those.
>>
>>
>>
> Yes, the are supposed to be bubbles.  I'm not sure what I'm doing wrong 
> yet, but I have noticed that effect.  They are isosurface shells with 
> very thin walls.  The material has an ior of 1.33, which is wrong and is 
> probably causing the issue.  I guess a soap bubble has an ior pretty 
> close to 1, so I'll have to play with that.  I think when I was trying 
> to get the irrid right I pushed the ior back up, but got that side-effect.
> 
> The balloon isn't quite right either.  It's too glossy so it looks more 
> like glass.
> 
> I think the cracks need to line up with the cracks in the foundation as 
> well.  More things to play with.
Check with your isosurface that it actually have an inner opening. 
Render just a single one cut in half using a difference or intersection.
Assuming that Bubble_Object is defined at the origin and having it's own 
texture :
difference{
	Bubble_Object
	box{<100, 100, 0><-100, -100, -100> pigment<1,0,0>}
   }
or
intersection{
	Bubble_Object
	box{<100, 100, 0><-100, -100, 100> pigment<1,0,0>}
   }
You need to see only a thin line of red around the shape. If the whole 
surface is red, then, it's not hollowed out properly.

The ior is correct. Bubbles are mostly water, and water's ior is 1.33.
The best/easiest way to model those is the difference of two spheres.
difference{
	sphere{Centre, Radius}
	sphere{Centre, Radius-0.001}
	pigment{rgbt 1}
	finish{reflection 1 specular 1 fresnel irid Value}
	interior{ ior 1.33 }
   }

The balloon need to have some blurring in the reflection. Probably also 
need to reduce the amount of reflection.

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"RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
> This is a work-in-progress inspired by a photo I took of my grandson
> chasing soap bubbles in his yard.  As usual, it was supposed to be a
> brief doodle, but has morphed beyond that.  I have started adding other
> things that "float" in various ways to model in the scene as well.
>
>
> --
> -- Chris R

I like the way you play. Why not use Iridescence on the soap bubbles?
That is what it was made for.
Have Fun!

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On 4/13/2024 2:55 PM, Cousin Ricky wrote:
> "RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
>> This is a work-in-progress inspired by a photo I took of my grandson
>> chasing soap bubbles in his yard.  As usual, it was supposed to be a
>> brief doodle, but has morphed beyond that.  I have started adding other
>> things that "float" in various ways to model in the scene as well.
> 
> Are those floating objects intended to be bubbles?  They look like solid water
> droplets.  Hollow bubbles do not invert the scene behind them.
> 
> The cracks in the pink granite blocks are conspicuously regular, but I'm sure
> you already have plans for those.
> 
> 
> 
I fixed the issue with the bubbles.  The objects were defined to allow 
for a variable wall thickness between 0.33 and 2 microns.  In my 
experiments the test bubbles were all 1 micron or more thick and they 
always looked right.  However, when I used a value < 1, I was running 
into the floating point range problem that was giving very weird results.

So, I changed the thickness range so no bubble is ever less than 1 
micron thick and now they look much better.

I'm playing with the fountain crack and the balloon texture now and will 
post an update later.

-- 
-- Chris R

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On 4/15/24 15:31, RATH, CHRISTOPHER A wrote:
> However, when I used a value < 1, I was running into the floating point 
> range problem that was giving very weird results.

Moving to a smaller isosurface accuracy setting(a) might well help too, 
if you've not already tried it.

Bill P.

(a) - As a rough rule, accuracy values of 1e-5 / 1e=6 are about the best 
we can actually achieve with isosurfaces.

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"RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:

> I'm playing with the fountain crack and the balloon texture now and will
> post an update later.

This is looking great - I think what you need for the balloon is
transparency/filter, double_illumination, and SSLT.

How did you make that cracked brick?   It looks awesome!

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Le 2024-04-16 à 06:33, Bald Eagle a écrit :
> "RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
> 
>> I'm playing with the fountain crack and the balloon texture now and will
>> post an update later.
> 
> This is looking great - I think what you need for the balloon is
> transparency/filter, double_illumination, and SSLT.
> 
More like back side illumination + radiosity with recursion_level 3 or 
4. That would simulate the thin walls of a balloon way better than SSLT.
Yes, add a small amount of filter.
pigment{Yellow filter 0.1}//maybe even less

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On 4/15/2024 1:03 PM, Leroy wrote:
> "RATH, CHRISTOPHER A" <car### [at] comcastnet> wrote:
>> This is a work-in-progress inspired by a photo I took of my grandson
>> chasing soap bubbles in his yard.  As usual, it was supposed to be a
>> brief doodle, but has morphed beyond that.  I have started adding other
>> things that "float" in various ways to model in the scene as well.
>>
>>
>> --
>> -- Chris R
> 
> I like the way you play. Why not use Iridescence on the soap bubbles?
> That is what it was made for.
> Have Fun!
> 
The bubbles do have iridescence; the bug in the shape is probably making 
it too hard to see.  I will probably put a few bubbles closer to the 
camera so you can see it better in the final image.

-- 
-- Chris R

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