Phase 2.

Practical Test:

 

Lidar scan of a car. It is common for us to scan all types of vehicles, from small cars to helicopters and jumbo jets.

The ideal scanning environment would be a stage with a solid floor and a minimum distance around the vehicle of 5 meters. In an interior scan, the vehicle will have minimal movement (outside, the wind will play a role). Consider scanning in this environment if possible and somewhere where people will not try to enter or exit the vehicle during the scan. Keep an eye out and stop people approaching the vehicle during scanning.

 

Consider how you will register the data if you are scanning outside (e.g. can you use nearby buildings to register the scans together) and ideally use targets so that registering scans will be faster and easier. In addition, if you are working outside, make sure the vehicle is parked in a good position (e.g. not under a tree).

 

When scanning outside, the weather also has a significant impact. Keep an eye on it throughout the day, and if it starts to get windy, note it in the shoot log. Windy conditions may also make elevated scans (those on stands) impractical, so inform production that it might not be possible to capture the tops of the vehicles.

 

Due to a laser's physical constraints, lidar scanners typically have trouble handling dark, glossy objects. Leica's RTC scanners are better than most scanners in handling dark surfaces, but they still fall short of where we would like them to be. Lidar scanners are a line-of-sight device that provide point data using the returning laser data. If you point the laser at a transparent, reflective, or dark (almost black) surface, the laser will be refracted, reflected, or absorbed, and the scanner will not receive the signal returned. This means that data for that area will not be collected.

 

If you have a black car (or a very shiny car), you should powder the car first before scanning. If they ask you to scan a black car, it's important to ask if the problem can be addressed and dusted off. If the car is a hero car, it may mean it is brought back for scanning after being used on set.

 

 

 

 

 

 

Lidar scan of any area. Environmental data collection can be performed using a variety of remote sensing techniques. Lidar is one type, an active system that uses light (in the form of laser pulses) to calculate distance. A LIDAR unit has a laser reflected by a rotating mirror, which sprays the laser beam onto the surrounding area and calculates distance based on phase or time of flight. This happens so fast that it can collect up to 2 million points per second and have a range of up to 1 km.

 

The Lidar scanner captures data in a 360 degree sphere from any setup, with a range of up to 1km (Leica P50) (120m for RTC 360). Lidar technicians need to move the scanner around and around the set to ensure it captures dense point clouds, covering all angles and ensuring the final model is occlusion-free. To achieve this, we have multiple setups at different heights for maximum coverage.

 

When registering scans, you should ensure that there are enough overlap points between scans for accurate registration. To do this, you need to think about which scans to link in your set and make sure there is enough duplicate data between them. Imagine that each scan is a piece of a jigsaw puzzle, and that each piece should have an overlap (at least 25%) so that when you put them all together to complete the picture, you know where each piece will fit. please. Before using lidar to scan a set or location, it's a good idea to walk around the area and plan a route to collect data as efficiently as possible. Ideally, you should move through the set in a logical process rather than jumping. This makes registration much more difficult and increases the chances of lost space as you don't know where you recorded from.

 

Important steps for LIDAR scanning:

 

• Walk through the set and make a planned route of where to scan from.

• Place tripod on firm ground and level the scanner. ALWAYS LEVEL THE SCANNER as these speeds up the processing and helps with the accuracy of the registration.

• Check to make sure there is enough overlap from the last scan.

• Plan next position to ensure overlap.

• Set correct settings and then scan from that position.

 

Photo scan of old nurse house including textures that I followed.

 

• Manual Photo scanning for props and sets:

1. Start with your Macbeth (color chart) chrome and grey balls.

• Make sure the entire prop is in the frame and you can see the color chart and the chrome/grey sphere from the front.

• Make sure the meter is not cluttered by the background and expose the props accurately. This is always a problem except on 11a where all the walls are white. Return to the measurement section for how to deal with this.

• Enclose it in parentheses. Once you have half the ball, take two more shots and spin the ball to capture the other side.

 

2) 8 bracket texture round.

• Change the camera's folder to keep the textures you want to capture separate from the reference capture you just captured.

• Move around the prop and capture 8 sets of images. If the chrome/gray ball blocks the prop, remove it for the rest of the shot.

• As you move around your props, be aware that you may need to adjust your shutter speed depending on the texture of what you're looking at and changing lighting conditions.

 

3) Photoscan - Wide

• The camera must be set to single frame, as photoscan data does not need to be bracketed.

• Circle the prop from the same frame as the texture. There are no hard and fast rules about how many frames or how many spins you need. It depends on the complexity of the prop. If you need guidance, prop rigs are designed to acquire very complex objects and take shots in 8 increments every 45 degrees, so pick from there if needed.

• Note that narrow prop corners should capture more frames, and wide flat surfaces should capture fewer frames. • If your prop is not high, you can also use this lens to do low-pass and high-pass from that distance. If your current lens has a prop that's too big to get through the high pass, you can switch to a shorter one to get a better angle.

 

4) Photo Scan - Tight

• You need to get up close to capture details or partially recapture the entire prop if wide angle shots do not provide enough resolution.

• If the prop is large, switch to a longer lens and take two more shots to capture more detail in the top and bottom halves of the prop (keeping the 30% overlap of course).

• Difficult parts of the prop should also be covered. B. Tops of tall props or complex surfaces that are not captured from a horizontal perspective. Don't forget to get quality textures in all areas of your prop.

• When performing close-up photo scanning, take this opportunity to ensure that the scale markings are well covered. We need 3 images with both markings and focus in the frame to match the rest of the prop.

 

5) Texture

• You need to capture the bracket texture from the following locations.

 

• Full screw, 8 turns in 45 degree increments.

• Top and bottom halves of the support, 8 turns (if the support is big enough)

• Flat textures on any plane

• The top and bottom of the support should be as flat as possible.

• All areas with intricate detail.

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