Some Progress on the HDR

CN-161124-0001_2_3_4_5 Panorama.jpg

I’ve had a lot of trouble getting PTGui to do it’s thing. However I have made some progress. This is the middle row of 10 images, all HDRs, stitched into a panorama. A few errors but not too bad. This is the LDR version of course. And my kitchen is a mess, I know. I’ll try to gradually add the other two rows, but I could probably work with this as the bottom row is only the floor. Maybe I’ll try it out with some simple shot.

Trouble in the Kitchen

PTGui set up, loaded up the 150 images, worked smoothly until… I’m using autobracket on my K5, set to Aperture Priority, so it changes the shutter speed only for the exposure bracket. However, that’s an auto-exposure mode, so if the light changes the actual range of shutter speeds will vary from one bracket to another. If I use Manual, it changes both aperture and speed to get the exposure change, and I can’t control that. This variation is shutter speed range is apparently enough to upset PTGui. I did shoot late in the day and the light probably changed a fair bit from start to finish.

So, either I need to not use auto-bracket, or hope that the light doesn’t change. Shooting in consistent light is probably necessary for a decent result anyway. The pano head should actually facilitate this as once the angle is set it just clicks around to the next position fairly quickly. I’m sure it would take a lot longer to do if I was using more primitive methods.

I was a bit bemused reading comments on a Pentax forum about settings for HDRIs. A couple of people commented that the dynamic range of the K5 is plenty and what need can there possibly be for exposure bracketing. I guess none of them even know about, let alone actually do, Image Based Lighting in a 3D rendering application.

HDRI Panoramas

Recently acquired a Manfrotto panoramic head for my tripod. Plan is to shoot HDRIs for IBL. Not sure if I’ll actually need customized HDRIs. In the film industry they’re important because the CG has to match the lighing in the live action, so an HDRI of the scene is almost mandatory. I did a workshop a few years back on Look Development and IBL with Noah Vice, who worked on Ironman and quite a few other well known movies. My needs are a bit less demanding, but I’m planning on using IBL extensively for a while. I’m waiting for my licence for PTGui to come through. I shot a series to process an hour ago in my kitchen. Should be interesting. Once I worked out how to set up the panoramic head it proved to be very useful.

Green Ceramic Bottle

render01

Quite experimental image – I’m trying to come to grips with IBL in Vue, and not succeeding very well. Different materials react in quite different ways to the lighting. Also I made the ‘bottle’ using a somewhat unfamiliar technique – bevelling a Bezier curve with  a custom curve profile. Being somewhat influenced by PBR concepts at the moment I’m tending to use more reflection and less spec on my materials.

Black and White

render01

This paving effect was achieved with a white image, some thin black lines drawn over the top and blurred a little. Then used as a displacement map for a plane (subdivided and UVd) in Vue. With a little extra noise bump then added over the top. Pretty quick and easy process. I can use this for the lanes and drains around here which are all paved with bluestone blocks. A bit of extra detail needed but the basic forms are good.

A Day’s Work

render02

Well, the paving stones are a single plane with displacement. It has worked fairly well, but was it worth it? Took me all afternoon to do. Sculpting is the other main option. I’m considering using displacement in situations where there are a lot of things that need work, such as the paving stones here. My main aim at the moment is to do some of the cobbled lanes and gutters around here – lots of squarish stones there, too many to sculpt really. I think displacement would be quicker, as long as it works properly. I must admit a lot of the time I spent on this was getting the vegetation correct, which wouldn’t be much of an issue with a gutter or lane.