portrait – How to get lighting text effect

I recently follow this account and really love how the text is projected on the model.

I tried doing it with a projector however the projector also projects black light and it does not give the same effect at all.

Link to image:
https://www.instagram.com/p/CRQM7nusDmi/

Image:

red text over model

writing cheek

How could I achieve that kind of effect?

PS: If someone also knows how to get this kind of red backlighting that would be awesome.

portrait – Different lighting setups for models with darker skin vs. lighter skin?

Disclaimer: I’m not much of a portrait photographer, and have never considered the differences between dark- and light-skinned models in my limited lighting setups. Grain-of-salt, and all…

When adding light, whether with reflectors, off-camera flash, studio lights, etc., knowing and controlling the ratio(s) of the lights is important. The ratio between ambient vs. reflected light, key light vs. fill light, etc., determines how the highlights and shadow areas of subjects interplay.

Photographer Kyle Cong wrote about this exact subject on his blog: Portrait photography how to: Photograph darker skin tone with off camera flash (also picked up and re-posted by PetaPixel).

Being a portrait photographer and have been using off camera flash for many years, I used to think skin tone is irrelevant to portrait lighting setup. … My first model has very pale skin, my lighting setup was perfect for the light effect I wanted. After I start photographing the second model who has darker skin tone, I realized that my first lighting setup is quite off. … Lighter skin tone will bounce more light which makes the shadow harder to preserve.

For this reason, when photographing people with lighter skin tone, our light needs to be positioned so the shadow will be protected. … To be more exact, the controlling of the ratio between highlight and shadow will be different.

… When placing a bright and dark subject right beside each other the bright subject will look brighter, the dark subject will look darker.

If we use our light on someone with darker skin tone in the same way as lighter skin tone, the shadow will look too dark (As I mentioned above, protecting the shadows). This will make the highlight appears brighter. So bright that they looks like hot spot even though nothing is over exposed. In other words the image will be too contrast. Lots of highlight and shadows but lack of half tone.

To fix this issue, we need to move the light a bit closer to the shadow side so part of the shadow will be lit as well. Remember just part of the shadow not all of them. Pointing the light directly at the shadow side will destroy your shadow and mess up your mid tone. The result will be a flat image with flashy look.

Cong’s blog has several photos which demonstrate his approach and results of changing his lighting for darker-skinned models.

lighting – Unity baked light messes up a set of objects

On a few objects I use a technique where instead of using geometry, I place planes with a Cutout Material on top of each other, creating a 3D illusion with minimal cost. The thing is, it looks great with Unity’s Realtime Lighting, but Baked Lighting darkens some of them.

The floor, walls and ceiling look close perfect, while the door’s details are completely ruined. This was the reason I stopped baking light, but that is not a viable option as I am aiming to make it a Quest 2 Standalone project. Without baking, it just can’t run it, with baking it is 100+ FPS on average.

I even turned off AO, just in case, but that didn’t work either.

After countless hours of baking I’m out of ideas and started to lean towards making the problematic parts with actual geometry. That could be a bit heavy on the polygon side, but I could then include that too in the main 4K Texture Atlas. I’m quite unsure if that would be such a huge performance hit if any at all (since I could get rid of 3-4 Cutout Materials, making the SetPass calls even lower), but I’d like to keep the current approach if possible.

Realtime Lighting: Note how well the color of the door detail and the door itself match.
Realtime Lighting

Baked Lighting: Now the door details are way too dark. Funnity enough the floor, walls and ceiling do actually look better baked.
Baked Lighting

PS: I know the baked image is a lot darker anyway, which is not intended and will be fixed if I find a solution to this issue first. I know how to add more strength to lights. πŸ˜›

opengl – Directional lighting messups with uniforms

Recently, I’ve been making a 3D game, and I have more progress! I am trying to implement lighting, but when I want to change the directional light uniform manually, it gets weird.

Here’s an example

When I dont use uniforms:

enter image description here

When I use uniforms (THE SAME EXACT NUMBER VALUES):

enter image description here

Its like the faces don’t register the Z value, or something. I have no idea.

Heres my shader code:

// FRAGMENT

#version 120

varying vec4 v_Vertex;

varying vec2 v_TexCoord;

varying vec4 v_Position;

uniform float f = 0.0;

varying vec4 v_Normal;

vec4 n_Normal;

varying vec4 v_Color;

uniform sampler2D u_Texture;

uniform float fac = 16;

in vec4 color;

vec4 texture;

uniform float x1;
uniform float y1;
uniform float z1;

float rand2D(in vec2 co){
    return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
}
float rand3D(in vec3 co){
    return fract(sin(dot(co.xyz ,vec3(12.9898,78.233,144.7272))) * 43758.5453);
}

vec4 directLight(in sampler2D tex, in vec2 coords, in vec3 lightCol) 
{

    float amb = 0.3f;
    
    vec3 normal = normalize(v_Normal.xyz);
    vec3 lightDir = normalize(vec3(x1, y1, z1));
    float diffuse = max(dot(normal, lightDir), 0.0f);
    
    return (texture2D(tex, coords) * (diffuse + amb) * lightCol);

}

void alphaTransparency()
{

    texture = texture2D(u_Texture, v_TexCoord);

    if (texture.rgb == vec3(1.0, 0.0, 1.0))
        discard;

}

void main(void) {

    vec4 fakeshading = vec4(1.0);
    
    float fac = 0.0;

    alphaTransparency();

    n_Normal = normalize(v_Normal);
    
    // gl_FragColor = texture;
    
    // gl_FragColor = texture;
    
    gl_FragColor = directLight(u_Texture, v_TexCoord, vec3(1.0, 1.0, 1.0));
    
}

and the code where I change the uniforms:


... code above irrelavant

shader.start(shader.getProgID());
            
            GL20.glUniform1f(GL20.glGetUniformLocation(shader.getProgID(), "x1"), 2);
            GL20.glUniform1f(GL20.glGetUniformLocation(shader.getProgID(), "y1"), 3);
            GL20.glUniform1f(GL20.glGetUniformLocation(shader.getProgID(), "x1"), 1);

Thank you for your help

lightning network – How can I see the on-chain evidence of a lighting channel?

I am learning about lighting now and I’m trying to check my understanding on-chain w/ a block explorer. I have opened several channels already and closed some also.

I would like to confirm my understanding of the script logic (e.g. the 2-of-2 multisig, the HTLCs, and the conditional refunds) as described in the lightning white paper and other sources.

Unfortunately the block explorers I have tried only show “OP_0 ” under the Pkscript fields for these transactions, Blockchain.com for example.

Is there any on-chain evidence of a lighting channel (before or after channel closure) or is that something that is discarded before settling on-chain?

Thanks in advance

lighting – Camera Slow To Respond When Trying To Take A Photo | Nikon D5300

It really sounds like the camera is using a long shutter-speed.

First, check the Mode-Dial. It is is not set to Auto or P, then the exposure depends on the parameters you have dialed. Move the dial to P and see if it solves your problem. If it does, good but you may want to learn about the Exposure Triangle if you want to take control of your camera and be more creative.

If automatic exposure still gives you a dark image, then you may have dialed Exposure Compensation up. That will give you a blurry but very bright image. To reset it, press the +/- button while turning the dial until the EC indicator is at 0.

The important thing to know is that even though you did not choose a slow-shutter speed (which is what you can do in S and M modes), the camera can still chose a slow one if you select too small aperture (which you can do in A mode). Finally, there is also ISO. In Auto mode, it is set automatically by default but in other modes it is fixed by default, although you can make it Auto or better, simply raise it to the needed level. In any case, the camera reports what shutter-speed will be used in the status line of viewfinder, so if you see 60 or a larger number (meaning 1/60s or a faster shutter-speed) than there should be little blur. If you see the number followed by a quote such as 8′, then that is an eight second exposure which is way too long.

lighting – Photographing darker-skinned people

The best way to do this would be to use a gray card to get the exposure just right. But it does depend somewhat on what you’re photographing.

If you’re doing just a head shot, use a gray card if you can first, get the exposure right for that famous 18% grey, and then shoot away. If you’re taking more of a full body shot, the skin color probably doesn’t matter a whole lot, the clothes will occupy significantly more of the photo. Actually, the clothes can be a problem for anyone’s skin color.

Likely you will want to do some checking in post and make sure the skin tones are comparable to what they are in reality. But you should be doing this again regardless.

Hope this helps!

lighting – Unity – How to get nicer shadows from distant point lights?

Increase Range.

If looks too bright decrease Intensity.

enter image description here

Range 130, Intensity 1.3, Anti aliasing 8x multi, Shadow Res Very high.
Distance between light and shadow receiver 30 Unit. Distance between light and shadow caster 25 Unit.

Point light is not usually used for distant lighting. Use a Spot light instead. Result will be better.

lightning network – Does got any optimise method can swap/splice/loop channel without on-chain cost in lighting node?

If initially the channels from Alice, Bob and Tom came from the same channel factory (we do not have channelfactories as part of lightning as they would be much easier to build on eltoo channels) then I guess Bob could easily be removed off-chain to have a new channel just between Alice and Tom.
As with current lightning network I think we have to hit the chain to achieve what you want

lighting – How to implement backscattering in Graphics3D?

First of all, I’ll explain what I mean.

Here’s a picture, where on the left is the result of

Graphics3D(Sphere(), Boxed -> False, 
 Lighting -> {{"Directional", White, ImageScaled({0, 0, 10})}}, 
 Background -> Black)

and on the right is a photo of the full Moon.

The Moon is not Lambertian

As you can see, the modelled sphere is brightest at the centre, but the full Moon is uniform. That’s because the modelled sphere reflects light using Lambertian formula, but the Moon is not Lambertian.

There’s a (quite recent) formula, where the author gives a nice physical explanation: https://arxiv.org/ftp/arxiv/papers/1808/1808.01024.pdf. Put succintly, the Moon has backscattering: the light is reflected mostly back to the light source, and its intensity is proportional to the cosine of the angle between directions to the source and the observer. When the Moon is full, the cosine is almost 1, and we get an uniform disk.

But it gets interesting when the Moon is not full. Of course, I could wrap the sphere in a calculated Texture, but that’s quite tedious when there are several objects. Is there a way to implement it in a more general manner, as something similar to Specularity?