Stylised photogrammetry…

•November 5, 2016 • Leave a Comment

I recently attended a workshop where the subject of stylised photogrammetry arose, in other words, 3D scanning stuff for purposes other than photo realism. Would it even be practical to scan objects for a stylised project when realism wasn’t the end goal? I’ve done some experiments on this before (I blogged about it here). I’ve recently blogged about scanning a human head and I thought I’d try a non-photorealistic application for it, by voxelising the scan and rendering it with SSS materials in V-Ray. I then took it into Prisma on my phone and ran some filters on it, see below!

Original scan work, the head scarf was scanned and provided by 3DScanLA

headscarfalt

And the sylised version!

headvoxels

After Prisma:

prisma

A header III…

•October 30, 2016 • Leave a Comment

Well here’s a frightening visage for Hallowe’en straight from the depths of the lab! Further research on my head scan below, started to patch up missing areas of the mesh and did some work on the albedo, roughness and SSS maps. It’s coming together slowly, more to do on finalising low poly topology and the other textures, cleaning up the hairlines etc. Rendered here in real-time with GI in Marmoset Toolbag 3, which is being released in November. Textures are currently at 2k and are holding up OK when close up.

Temporary low poly geometry wireframe

petemcnally_head_3dscan02_wireNormal map details

petemcnally_head_3dscan02_normals

Albedo, SSS, roughness added

petemcnally_head_3dscan02

Portrait view

petemcnally_head_3dscan03 petemcnally_head_3dscan04

A header II…

•October 18, 2016 • Leave a Comment

Some additional cleanup work in Zbrush here, where I smoothed out some of noise, added some more definition to the skin creases and created a displacement map from the original scanned diffuse texture for micro detail such as pores and stubble. It’s getting closer to something usable but still more work to do on the model and on the diffuse and displacement maps.

petemcnally_punkscan_head_cleanup

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A header…

•October 4, 2016 • Leave a Comment

I scan rocks. Lots of rocks. Rocks are good. Rocks don’t move, aren’t squishy, aren’t affected by wind and stay rooted in place if you have to leave the scene and return- rocks just make great scan subjects. Humans are different for obvious reasons, a stifled smile, a muscle twitch, a weight shift or a rumple in clothing caused by a draft are all enough to throw off a 3D scan when using photogrammetry. It’d be great if the same cheap 3D scanning technique that works so well for large static objects worked for humans but unfortunately it doesn’t, the best human scans come from expensive multi-camera rigs that folks like James Busby use to get scans like these. Maybe a detailed mannequin or waxwork would do the job but those are hard to access, people are everywhere but it really takes a patient subject to be a good model for single camera photogrammetry. They’re gonna have to sit or stand still while you orbit around them clicking away with the camera, fix their gaze at a point in space, control their breathing and be prepared to start the shoot from scratch if they have to move for whatever reason. Then they have to be OK with you using their likeness, it’s all a big ask if you’re not paying someone, that’s where family and friends come in!

For the past few weekends myself and my kids have been taking a swing at handheld human scanning. First we tried my eldest son as the model with me taking the photographs, but after a few tries he decided he just couldn’t keep in the laughing and quit on me! So we swapped roles, I set the camera up on a tripod and gave him a remote shutter release and showed him how to frame and focus, and I took a seat in the garden. I closed my eyes to make it easier to hold still, scans like this often have trouble with resolving reflections in the eyes and can leave the area very messy. My son took about 22 photographs in a 180 degree orbit, in a single row from right to left then back again. When I took them back to the PC for raw processing I saw that less than 14 images were in proper focus, the daylight had faded by then and it was too late to reshoot. We had tried hard and rather than see the session wasted I quickly masked the images and threw them into Photoscan anyway. Now, “garbage in, garbage out”, as the saying goes in VFX, and here the results were predictably less than stellar but actually not a bad starting point, definitely salvageable with a bit of patch up work and some sculpting in Mudbox/Zbrush – it’s all practice for me right now anyway. This is what the raw mesh looked like out of the box, rendered here in V-Ray using the Fast SSS shader:

petemcnally_punk3dscsan_head

There was more daylight on one side of the head so detail on the right was more accurately resolved, on the side with less light you’ll notice the ear wasn’t captured and there is more noise present around the beard and nose, this is also due to involuntary movement. The noise is more visible from the surface normals (click the image for higher res version):

petemcnally_punk3dscan_head_normals

So, although some micro detail was captured, like the forehead wrinkles and some skin blemishes, the beard and hair are a mess of wobbly noise. This should be fixable in Zbrush (or with, you know, a comb in real life) and I’ll also mirror the ear to the other side and try and patch that up. I managed to get on the beta of Marmoset Toolbag 3 a while ago, here’s a very quick low poly normal mapped version using the skin shader and some secret sauce:

petemcnally_screenshot014

And lastly for now, a cover for my forthcoming* album made from a decimated low poly copy:

today8bit

In the next post, I’ll cover some of the cleanup work. Thanks for reading!

 

*Not forthcoming.

 

 

Quigley’s Rock…

•September 1, 2016 • Leave a Comment

Recently I spent a week in Inishowen, Donegal where I took a tripod, monopod, laser measuring tape, Macbeth card and a Nikon DSLR with the express purpose of taking a holiday but also doing some proper 3D scans when I could🙂 Long photogrammetry sessions were impossible on some coastal trips up there, but I did manage to get quite a few partial scans, three or four decent ones and I learnt a truckload during the exercise. Right now I’m in the process of trying to mesh the scans and break them up into usable modular assets as part of a full “Irish Coast” biome, including LODs at 16k, 8k, 4k and 2k tris.

I’ve refined my pipeline a bit too, incorporating Substance Painter 2 into the mix (it has useful simultaneous multiple texture painting features that have been a huge time saver in the mesh cleanup process) and I’ve had a look at Megascans too, which promises to be an essential part of working with PBR. Here is one of the scans that required the least amount of cleanup, click for large versions.

Petemcnally_rocks_cframe02

Petemcnally_rocks_cframe01

Petemcnally_rocks_cframe03

Petemcnally_rocks_closeup

 

Here is a comparison of the LODs, from 16k tris (nearest) down to 2k at the back

Petemcnally_rocks_LOD_wire

Petemcnally_rocks_LOD

 

Finally, here is a link to a Marmoset Viewer version that you can navigate in realtime on my Artstation page. (You can move the light by holding shift and mousing around)

 

 

 

 

Lookdev experiments II…

•August 9, 2016 • Leave a Comment

As you’ll have noticed I’ve been running a lot of art through Prisma lately, don’t worry, it’ll stop soon. But not before I post some of my experiments in non-photorealistic rendering!

While looking through Google Photos the other day I searched for “rocks”, I was sure I had taken a bunch of landscape pictures ages ago for scanning that I hadn’t used and the search turned up a few. These were taken about 3 years ago, on a smartphone, while pushing a buggy on a broken path, so the quality wasn’t particularly good. I figured if they wouldn’t cut the mustard for a realistic prop, I’d try something non-photoreal with them, maybe something that might feel at home in Okami or Child of Light. Although Agisoft Photoscan processed them into a 3D model quite well, there were some large holes which required fixing in Mudbox, and also missing texture information which I’m currently patching up. I made a low poly version and unwrapped it, baking out normals, ambient occlusion and albedo from the high res scan. I took the albedo texture generated and painted over it in Photoshop using some custom brushes and standard filters to see how if I could get a hand painted feel (the Prisma servers were down, this happens a lot!). I then applied similar techniques to the normal map, removing high frequency detail and generally softening most areas. I also added some geometry for a cel-shaded outline effect. Here are the results of this in real-time:

Prisma came back up last night and I ran the albedo through some of the filters that wouldn’t change the hues too much. Here is where I started:

petemcnally_NPRrocks01

Here are some of the filtered textures, rendered in Marmoset Toolbag 2:

petemcnally_NPRrocks03

Lastly:

petemcnally_NPRrocks02

 

 

 

Lookdev experiments…

•August 2, 2016 • Leave a Comment

I’ve blogged before about sculpting some Batman character busts for 3D printing, there are now more than a few littering my desk at home, some finished, others abandoned. I was looking for something to run through the Prisma app on my phone and picked some Joker and Batman prints that I made last year. I ran each image through a number of filters and saved out the results, then hand painted some colour layers and lighting enhancements and composited them together to achieve the looks below.

petemcnally_BATMAN02

petemcnally_Joker_08

petemcnally_Joker_09

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