Garstor's World, My realm of 3D art, LEGO and atheism

Archive for the ‘Ray-Tracing’ Category

Unwrapping A Celtic Knot Design

Friday, March 3rd, 2017

This was an interesting problem. On the surface it seems easy; however, as you consider the options as modeler and texture artist, complications arise.

imageA good friend of mine was modeling a Celtic Knot-like headpiece for a staff. She graciously permitted me to record a video about my attempts to unwrap it with UV Layout.

As I hopefully make clear in this tutorial, this is a question of trade offs. We can create rectangular strips that are easy to paint on and very nicely fill the UV space. However, they will contain UV stretching or compression distortions.

Or we can remove the distortions but have oddly shaped UV shells to paint on. The end result will probably look much better at the cost of the effort required to paint on it.

After I posted this to my YouTube channel; I thought of a possible hybrid solution. I may experiment with that over the weekend and write about it here if it bears useful fruit.

Poser Lights

Wednesday, February 22nd, 2017

In a word: FRUSTRATING!

At least so far. Maybe I’ll learn a few tricks to make this easier in the future.

Blade Maiden - my light rigI deleted the lights that start with the default Poser scene. Since I wasn’t comfortable editing them yet, those were what I had been using to this point.

However, lighting is a big part of the story-telling with any image that one creates – whether hand-painted, photographed or rendered with a 3D program. So I had to change things up in order to better convey what was in my head with this scene.

Since I envisioned the Blade Maiden rushing across a stone bridge to commence battle – perhaps over a pool of lava – I started with four area lights beneath the camera frame. Two pair on each side of bridge, one with a reddish colour and one with an orangey colour. Instead of allowing them to cast light straight up, I angled them slightly to better illuminate the model.

There is an infinite light above the scene to add some daylight to the mix. This was one of the things that I found very difficult and annoying to control in Poser. So it could be better. The blade edge seems to have picked up so specular highlights from this light though.

The last light – also one that gave me problems – is a spotlight behind Blade Maiden to act as a rim light. She needed to be separated from the dark background. But this light gave me the most trouble. I could not figure out how to illuminate only Blade Maiden. Positioning the light in the scene was more trouble than it was worth.

I certainly have more to learn. However, at this moment, I find lighting to be much easier in LightWave than in Poser.

Playing With Poser

Sunday, February 12th, 2017

Although I (mostly) like how this turned out, I am still putting into the WIP album.

Blade MaidenThere is a lot that I need to learn about Poser still. Especially the texturing.

An early draft of this used a red & gold texture set for the Blade Maiden outfit. But the specular and reflection settings were running away from me; I couldn’t get them where I wanted.

So I opted instead for the more subdued tan texture set.

I wanted to get out of the blank “room” that is the Poser default scene. So I added Jack Tomalin’s Cliffhanger product. I bought this years ago when I was still using Carrara but today is the first time that I have put it into a scene.

This render still uses the default lighting rig that Poser starts with. I’ll have to start experimenting with lighting in Poser soon.

More Terrain Work

Monday, February 6th, 2017

Sandstone Ridge #4I had another burst of experimenting with rendering World Machine terrains inside LightWave.

The most serious issues have been worked out now. Here is the last render I created.

The normal map is solved. World Machine uses a Direct-X normal map, so I need to invert the Y-channel to get the OpenGL normal map format. The end result is better looking erosion lines that no longer appear to be vascular pumped veins throbbing across a power-lifter.

You will notice some odd stretching in the sky. That problem is also solved – I just did not upload a new version to Flickr. As it turns out, Image World is not the best answer for displaying HDRI sky domes. Image World is best suited to HDRI light probes and is not usually meant to be seen in the final render. I am using a Textured Environment using spherical projection for the sky dome now. That correctly renders the sky and clouds without distortion.

Alien LandscapeIn a very happy accident, I began exploring the new GeoGlyph 2.0 plugin for World Machine. Taking a cue from the work on “Sandstone Ridge,” I wanted to enhance the look of the erosion lines and get a more rock-like look to the terrain.

What came out immediately reminded me of some non-terrestrial planetoid. I instantly imagined a star field and nebula instead of an Earthly sky dome.

I also wanted to use the erosion to hint that there may be something else below the surface. So I made that a yellow-gold blend to mix with the brown and grey of the rock.

Instead of Textured Environment, I simply created a huge rectangle to act as a backplane. There is a slight curve to it but I don’t think that comes through in the picture. I used the Filter Forge plugin for Photoshop to create the star field and nebula.

Since it is in space without any atmosphere, the key light is a Distant one. This creates very hard shadows and you can see the light angle puts much of the left-side terrain into darkness. Behind the camera is a very large Area light that uses some of the green colour from the nebula. This light is very faint but it fills in some of those shadows a little bit.

I think it is time to return to building my skills with Poser and ZBrush.

Improvements On The Terrain

Tuesday, January 31st, 2017

I have been experimenting with the new terrain, trying to work out some of the issues.

The default “size” of a terrain in World Machine is 8 kilometers square. But this is completely relative. The main output from World Machine is a heightmap (or optional OBJ mesh) and colour textures.

Sandstone Ridge 2When I open the OBJ file in LightWave, it is only 1 meter square. So I have been scaling it up by a factor of 8,000 so that it “matches” World Machine. This had the unintended effect of diluting the normal and bump map effects that I was trying to introduce.

This time, I only scaled up the mesh to be 100 meters per side. This brought out the normal and bump effects. It also revealed another issue – the normal map should be producing erosion cuts into the rock. However, these are looking like veins on a steroid-abusing power lifter’s arms!

I think I know the cause though. The OBJ file is using the Z-axis as “up.” Carrara did the same thing. In LightWave the Y-axis is up and I have rotated the mesh to fit LightWave. So I need to adjust the normal map, either in LightWave or figure how to adjust it in World Machine. That will be what I experiment with tonight.

The sky is darker than before. I previously adjusted the brightness in the LightWave Image World tool. This caused too much light from the HDRI and I had to reduce the effect of the global illumination. This is not the best solution. I now know that the HDRI gamma needs to be changed.

So I am slowly getting there. Pretty soon I should be able to create good looking terrains on a regular basis.

A Bit Of 3D News…

Monday, January 30th, 2017

It will be good to get another post in before January ends. I have been playing around a lot with 3D this month but none of it was really worth blogging about.

After a long hiatus, I bought several more Photoshop Actions from Sevenstyles. They include:

I definitely need to acquire images – either my own photos, stock or renders – that I can use these Actions on. There are even more Actions that have been created since I last purchased. Sevenstyles is quite prolific.

Sandstone RidgeMost of my work this past month has been with World Machine and GeoGlyph. I just bought the upgrade license to GeoGlyph Professional v2; this brings some very large changes from the Indie v1 license.

This area is where most of my experimenting has not been worth showing off. But this past weekend, I came up with the following. It is still a work-in-progress but at least it is worth sharing.

I bought an HDRI sky image from CGSkies. They are fairly expensive at about $30 USD per sky; but they do add a lot of realism to the lighting. Most HDRI sites include a ground with the image, but CG-Skies removes that and has just the sky. I’d like to buy more skies, but we’ll see…

My biggest complaint with this image is that it is too smooth. I have not been able to pop out details with a normal or bump map. Hopefully I can get that bit figured out and start producing landscape renders that are really nice.

Happy New Year 2017!

Friday, December 30th, 2016

Happy New Year - 2017I started working on this last weekend; so I definitely had a looming deadline from the start!

This is one of the few times that I have managed to see an idea in my head come all the way to completion. Well, close enough to completion. As they say in the art world, “You never finish something; you just stop working on it.” Most of my original vision is contained in this render.

The room was done with LWCad. There are windows behind the camera because I planned to have image-based lighting. I may return to that idea in the future. LWCad also created the moulding for the walls – I love the Engraver tool! It makes short work for things like this.

The marble plinth was the first thing that I created. It’s texture comes from Substance Painter. I originally wanted to add some gold flecks to further catch the light. That is another idea that I’ll have to return to in the future.

The numbers started in LightWave easily enough. I imported them into ZBrush to attempt some retopology with ZRemesher. I still have a lot to learn on that front. While I did get tris and quads out of it instead of the horrible n-gons, the meshes are still not as clean as I would like them to be. As such, I didn’t UV map them. Their texture uses procedurals with a LightWave dielectric material.

Last night, I tweaked the placement of two area lights and got the happy accident of the caustics. I love caustics!

Finally, to break up the colours and draw the eye a bit; I did a cloth simulation. One of my 3D friends really hates the addition of the cloth! While it is not 100% of what I wanted with it, I do like how it came out.

There’s plenty more I could tweak and add. But this is the final version for now.

2017 New Year Render

Tuesday, December 27th, 2016

2017 New Year - work in progress

This image is still very much a work in progress. There is still a lot of things I need to add and improve here. Most notably, I have yet to model some baseboards. I should also create some ceiling trim while I am at it.

Everything was modeled in LightWave; however, the numbers were imported into ZBrush for retopology (done very badly by me). Texturing for the room and the plinths was done in Substance Painter. I quickly realized that I don’t have substances for wall paint or for the wood parquet flooring that I originally envisioned.

Because the numbers do not have UV maps, I used a procedural flakes noise to drive the bump of a LightWave dielectric material. I was aiming for a cut-glass look; none of the green colour has come through though.

More tweaking to do here. Hopefully, I can complete this on time.

ZBrush At Last!

Saturday, December 17th, 2016

Yesterday, I finally bought ZBrush 4R7.

I have debated this purchase for a long time and decided that a Saturnalia gift to myself this year was reasonable.

One reason for the delay was waiting for an entirely 64-bit release. I had thought the 5R series was finally under development when Pixologic announced earlier this year that there would be a 4R8 first. Not a devastating knock against them, but mildly disappointing given how long 64-bit systems have been available. I started at Microsoft during the shift from 32-bit to 64-bit; so 12+ years on is really a bit much to wait for a change like this.

Virtually every page of the 3D World and 3D Artist magazines features ZBrush work. It certainly is a must-have tool for the industry.

My last objection was training. ZBrush forces some big conceptual thinking changes on a 3D artist. But since I have access to PluralSight, Learn 3D Software and was recommended Michael Pavlovich’s videos, I really have no excuse any more.

I’m looking forward to putting ZBrush into my workflow. And I look forward to sharing the results of my creative efforts with the world.

Getting Caught Up On Stuff

Sunday, December 11th, 2016

Screaming up again on a month without a post here. Let’s fix that.

I hinted at a sore throat and that sumbitch only just went away in the last couple of days. It was about two weeks of an actual cold and then two weeks of a dry, scratching throat. It kept me coughing and making ahem sounds.

Black Friday and all the days leading up to Christmas Eve are super-busy for work. As a payment processing company, you expect that. The entire team is essentially on-call right now. Officially, I’m on-call next Friday. Fun!

I have finally re-installed all my SevenStyles Photoshop Actions into PS 2017. Brad has been busy creating even more Actions, so I’ll have to buy more in the near future.

In spite of the sore throat, I have recorded more videos about using Headus UV Layout on my YouTube channel. I was asked to do videos about unwrapping a human model; so I undertook the challenge. I used the free MakeHuman tool to get a female model and then set out to create 3 UV Maps rather than the single UV map produced by MakeHuman.

In the very near future, I am also going to take the plunge into the world of ZBrush. There is definitely a lot to learn there.

I am hoping that all of this will take my mind off of the looming disaster of President Trumpycakes.