shadows casting

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enzolima
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shadows casting

Post by enzolima »

This is a topic to explain my point from the pic in the PG.

Here's a pic with annotations:

Image

It shows that according to the starbase lighting, the light must be coming from the right. However, the ship would show shadows from a light source located behind the camera. So... there are two different lighting setups, for the ship and for the station.

See? In the circled part there should be some shadows.
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Sherlock Holmes
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Re: shadows casting

Post by Sherlock Holmes »

Trust me Enzo. That is where the sun is. I never put the sun behind the camera. Look where the neck is meeting the saucer. The saucer is casting a shadow. If there is not a shadow, then there is not supposed to be a shadow
If you eliminate the impossible, whatever remains, however improbable, must be the truth- Sherlock Holmes

enzolima
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Re: shadows casting

Post by enzolima »

Sherlock Holmes wrote:Trust me Enzo. That is where the sun is. I never put the sun behind the camera.
So the light IS originating from the arrows that i drew?
Look where the neck is meeting the saucer. The saucer is casting a shadow. If there is not a shadow, then there is not supposed to be a shadow
Are you not even seeing the circle i drew? Perhaps i should make a re-render to show you.
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Sherlock Holmes
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Re: shadows casting

Post by Sherlock Holmes »

Enzo, your really starting to annoy me and your beginning to insult me as an artist as if i dont know anything about shadows. Yes i see your circled area. Take a model outside, with the sun at that angle. The Shadow casts up on the hull, where the pylon blocks widens. If you look closely, you will see that the pylon is casting a shadow on itself (Where it Widens). IT then bends the shadow directly behind it, at that angle whatever is left of the shadow is being pointed behind the pylon in the blindspot where the pylon obstructs its view. I Also studies weather or not there should be a shadow cast on the other pylon and nacelle. Therer shouldnt, as any shadow is pointed between the nacelles toward space. Also, If you look at your little circled area, the "Cover" around the shuttle clam doors are casting a shadow. IF i did not have my sun lamp casting ray shadows, that would definatly not be present.
If you eliminate the impossible, whatever remains, however improbable, must be the truth- Sherlock Holmes

enzolima
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Re: shadows casting

Post by enzolima »

Ok.
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Raul Mamoru
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Re: shadows casting

Post by Raul Mamoru »

Mr. Sherlock Holmes and Mr. EnzoLima,

I recreated the scene using some of my meshes.
And the result of lighting is there. It was not easy to achieve this result.
After several "ActiveShade" and "renders" I came to this almost convincing illustration of a real scene.

The elements were placed in the same scene, but each element has received an exclusive lighting.

For me, the lighting and the presence of shade were essential for the brain "accept" the scene and its effects.

What do you think?
Attachments
Enterp-Spacedock shadow cast-001.jpg
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Raul Mamoru
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Re: shadows casting

Post by Raul Mamoru »

Now, with the addition of shadows, the scene imagined by Sherlock gains more depth, emotion and a breathtaking realism!

Lighting is one of the most complicated parts of the CGI.
A well-shaped mesh loses half its value without the correct lighting.
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JJprise_and_Spacedock2a.jpg
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enzolima
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Re: shadows casting

Post by enzolima »

Thank you. Both renders showed very good what i meant. Thanks for taking the time, guys.
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Sherlock Holmes
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Re: shadows casting

Post by Sherlock Holmes »

THose are great renders dude, but the shadow modification of my render, it looks like the sun is above the ship. Keep in mind that this is not a light bulb only a few kilometer away, the sun is a MASSIVE collsal object that emits so much light that it overwhelms an object. Shadows will be very limited. The way it is now, your going by effects of light in a room.
If you eliminate the impossible, whatever remains, however improbable, must be the truth- Sherlock Holmes

Raul Mamoru
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Re: shadows casting

Post by Raul Mamoru »

It's true: the sun is colossal. Your light surrounds the object on all sides. In space, there are at least two light sources: The Sun and the light hitting the atmosphere.
I remember the images from NASA: The Space Shuttle has no shadow, the effect of radiosity is very strong. The effect of this light is nearly: (Image 1)

See the image 2, where is the sun? But at the same time note a spotlight coming straight from the top between the nacelles.

The important thing is the final effect, the impact of the scene, the outline of the main characters in the scene. Thanks to the many additional spotlights, we have an image that moves: Lights, colors, and shadows. (Image 3)
Attachments
Search4Spock SpotLight.jpg
TheVoyHome SpotLight b.jpg
TheVoyHome SpotLight a.jpg
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Erik_Timmermans
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Re: shadows casting

Post by Erik_Timmermans »

What Raul really demonstrates well, is that the original picture by Sherlock Holmes is perfectly correct with the sun as a light source far away. Since it is at a great distance, the angle of the light is easily wide enough to shine on the base, and on the ship's main hull. This in itself is perfectly fine.

In space, radiosity and reflections are added as well. Aside from that, we as humans aren't used to 'realistic' pictures from space, as we have no frame of reference except for some (usually touched up) photo's from Earth orbit, and special effects scenes from movies. Our minds combine what we have seen before and what we see here on earth, to create an expectation of what is 'real' and as such we define which image we accept as realistic and which one we rate as artificial. This can vary from person to person, and may require a CGI scene to have lights added in places that would not have light in real life, simply to get the images accepted as 'real.'

As Raul says, good lighting is the most complicated aspect of CGI, and in the end, the judgement of the result will always vary between people. (Just look at the discussions on the ST movie all around).

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