# BB-8 and Dalek rigs and realistic materials?

• @ZachAlan_Productions

refractive index = index of refraction

• @JMcAllister makes sense, but what is the refraction amount for and why would I change it?

• @ZachAlan_Productions no idea. (hence I said nothing about it)

But refraction is something that happens when light passes through a transparent object, so I would guess it's how much the refraction is blended with the original?

But like I said, I don't know.

I was just pointing out that "index of refraction" and "refractive index" are interchangeable terms and mean the same thing

• @ZachAlan_Productions

Have you seen this?

http://hitfilm.com/reference/hitfilm-pro-2017/index.html?setting_up_materials.htm

The index of refraction sets the amount of refraction, which differs depending on the density of the material the light is passing through. The refraction amount determines the visibility of the refraction.

• Moderator

Yeah to rephrase the above answers in a slightly different way, Index of Refraction/Refraction Index, etc, measures how much light rays will bend when crossing one material to another.

Vaccum is an index of 1.0. Light isn't bent by a vaccum. Air is roughly 1.01 or so. Water, about 1.33 or so. Etc.

• Moderator

Ooops, missed parts of the question.

Roughness in Cook-Torrance. Imagine the surface of an object is covered in tiny dimples, like the surface of a golf ball. Roughness is the depth of the divots. 0 roughness has zero depth for a perfectly smooth surface. 100 is very deep divots.

These divots would scatter light rays. So, increasing roughness makes a specular highlight dimmer and larger/more spread out.

Adjusting specular reflectance (think of this as how deep a like ray goes into a material before bouncing. Not quite subsurface scattering, but close) and roughness change the look of a specular reflection, along with the reflection amount (master strength of specular reflection).

So, those three faders together affect how speculars look. Fresnel also affects speculars (providing a color cast as the object's angle, relative to the light, changes. The specular color also affects how the specular looks.

Turning up roughness should help give a more worn look. You can also turn down reflectance and reflection to dull the highlights.

Another option is creating a specular map, which requires the model having been UV wrapped (I think the Dalek is. Certainly its head is.).

For specular maps, I turn you over to Simon Jones who gave a great walk through in this old Hitfilm 2 tutorial. Skip to about 3:20..

https://youtu.be/RG4wTsEC3Vo

Actually, just watch the whole thing. The interface is different, Hitfilm 2 doesn't have Cook-Torrance shading and Hitfilm 2 doesn't have individual parenting for animation groups, but this is still a great tutorial and covers a couple of more obscure settings like emissive color, goes over loading multi-part models and has other misc information that's good to know... For example, bringing in a "Normalized" model will scale it to fit a 500x500x500 box.

• @GrayMotion just read through it. Really helps understand the settings! Thanks for the link!

@JMcAllister Thanks for the quick response, I wasn't sure for sure because I think Triem said something about it earlier and said refraction setting not index or refraction setting...

@Triem23 thanks for that explanation! Really helps me understand these settings. I'll have to mess around and try to get the right look....

• Moderator

No problem Zach.

@GrayMotion I think it was for you that I typed up a breakdown of all the Cook-Torrance settings. Do you still have that? I'm too short on time to search my thousands of forum posts to find it, and probably too lazy to type it up again until I'm preparing the relevant Hit-U tutorial.

• @Triem23 is it even necessary to find the material setting online?

For example, the gold from the website you linked created a nice polished gold, but not the more matte painted gold from the show.

Would it be easier to create the material from scratch, or use those settings and adjust? To make it more accurate could I reduce the specular reflectivity to make it less mirror like, and then add roughness?

• edited October 2017

@Triem23 I looked around in my previous posts for the write-up I thought you did..but I cannot seem to find it. You've dropped so many tidbits around that its hard to put my finger on them now.

I only found this so far:

http://hitfilm.com/forum/discussion/comment/96110/#Comment_96110

When I find more I'll post so that @ZachAlan_Productions can have a view of the entire picture.

Edit:

Master @Aladdin4d dropped this January 2016:
https://hitfilm.com/forum/discussion/39446/cook-torrance-references

• @GrayMotion

Thanks you! That IOR list is quite useful!

@Triem23 just looking at some reference photos of Daleks from the show, the default Dalek materials, with phong shading and no textures, seem to look quite good as the plastic material from the props. I also added a lot of diffuse reflectivity. It also seems quicker to render.

I might try this look for now, and do the animation test with some real footage. I'll then post it and see what you all think...

• @Triem23 Did you happen to get that material website link off of your PC? Whether I use it for this project or not it would be handy to have access to such a resource. Thanks!

• If I want to use the model rigs in a video, do I need a spherical environment map image of the location, or will a normal panoramic photo work as well?

I can't find any 360 apps that work well with my phone camera because of some lens distortion.

• Moderator

A true spherical wrap will work BETTER, because it will have full surrounding data, but a regular panoramic photo will work pretty well. I've even had shots where I didn't have a sphere or linear panorama so I made a comp shot twice as wide as the the BG footage, moved the BG footage into it, duplicated it twice, shifted the duplicates left and right to fill frame and flipped the duplicate scale to -100% on the X-axis to make it seamless.

Unless you're doing a large object that's super-reflective chrome, no one will notice the reflections are cheated.

Remember, a 3D model can use the entire comp shot itself as the environment map--that wouldn't be a sphere, but it always looks good.

• @Triem23 Thanks for the info! I discovered a downloadable 360 mode for my phone camera that seems to work decent enough. There are some harsh lines where the images don't quite line up, but that probably won't be visible as a reflection, plus I might blur the image a bit.

Also, is there a way to reduce a model's texture opacity in Hitfilm? The Dalek would look a lot nicer if the dirt textures weren't so intense. . .

• Moderator

Can't change the opacity of a texture map in Hitfilm. I think Hitfilm takes PNG textures, so you could adjust the map in a photo editor.

• @Triem23 I reduce the opacity in a photo editor, but when I apply the texture that section of the model is transparent. I would like there to still be a solid diffuse color underneath. Any ideas?

• Moderator

In the photo editor, stick a layer underneath of the diffuse color of the Hitfilm material. Adjust dirt opacity over that, and export with the background color. Bake it in.

Might need to set the diffuse in Hitfilm back to 50% grey.

Save this as a variant project file. Don't overwrite the current version.

• @Triem23 that makes way more sense... I'll try it.

I also discovered why your BB-8 reflections were upside down. It's because it was the index of refraction's reflection, not specular reflectivity reflection. In Hitfilm the IOR is an upside down reflection of the environment according to the manual linked above.

• Moderator

Ah, so I had Refraction cranked.

• @Triem23 I can't find any good reference for a bronze material on any of the sites. Is there another similar material that will give a similar look to the bronze of the Daleks?

I have a handheld shot I tracked and solved of my living-room and a spherical panorama and I'm trying to get the Dalek looking like it was taken from the show, or at least realistic enough. I might share a clip of what I have so far.

• edited October 2017

Here's a test:

The track isn't the best, I think because the ISO needed to be to high which makes it jitter a little.

A have a point light about where the lamp is, and a higher intensity point light where a big window is.

Any recommendations for better lighting or materials (or anything else)? The Dalek has the default materials with some diffuse reflectivity and toned down diffuse and bump maps.

• Moderator

Bronze is an alloy, usually about 85-87% copper, about 10-12% tin with the rest being, well, something else. Often aluminum. In a pinch, treat bronze as copper with a little extra green.

Not seeing a link for the video test?

• @Triem23 sorry I saved a draft for the post as the video uploaded. When I came back to post it Hitfilm's site was acting up. There was no box here for me to type, and the page wasn't loading. Neither was the account page. Weird. I'll edit the above post now...

• Moderator
edited October 2017

Yeah, there was a glitch on the forum earlier. Looks like they fixed it. :-)

Actually, not too many notes. I think I'm make the fill light off to the right a bit more blue to match the spill light from the window, and I feel the Dalek is a little short (The Bronze Dalek was built so it's eyestalk matched Billie Piper's eyes, so the eyestalk, when level, is about 5' 2" up). Maybe turn the fill light intensity down a bit? Looking at the couch it seems most of the light is coming from the lamp in the corner, although you might have light sources I can't see out of frame.

Ah, assign an environment map to the Dalek in the material settings for it's layer. Go ahead and use the Composite Shot it self. Double check and make certain there's specular reflectivity on the chrome parts. That should get some room reflections in the chrome of the eyestalk, sucker arm and gunstick.

Only other thing I can think of if maybe the diffuse color for the skirt and the cage of the neck. Those shouldn't be any darker than about 16,16,16 or so. They might need to be adjusted depending on whatever footage you're compositing into, but right now it's reading a little dark to me when compared to the deepest shadow of the footage and those picture frames on the right.

Otherwise, it's a really solid composition, and whatever grading you'd do later in the shot will finish unifying the Dalek with the BG plate.

• Thanks a lot @Triem23 !

Before I was using phong shading, but now it's cook-torrenece with a copper fresnel.

What do you think?

• Moderator

I say we compare your render to a screen shot from an actual Doctor Who episode or two.

http://www.evilofthedaleks.co.uk/images/parting-of-the-ways-black-daleks.jpg

The first shot is CG Daleks from "The Parting of the Ways." The second is the prop from "Dalek."

So, compared to "Parting of the Ways," the collar and sensor bumps are just a tad bright, but, if you look a the prop from "Rose," that entire Dalek is duller and darker.

Now let's look at "Asylum of the Daleks."

Ok, those Daleks are all yellower overall.

Point being, Dalek props get repainted and their colors change over the years, so the real question is how are specular highlights and reflections matching?

Answer. Damn well. I think you've gotten your Dalek tweaked out and ready to use and I think your renders hold up to the actual show...

Looking at the two renders really shows what a difference Cook-Torrance makes.

• That looks great! But still doesn't look real, at least to me...

-the volumetrics (or whatever they are) are inconsistent with the other light sources, looks super-weird to my eyes

-Seems like the model isn't casting shadows on itself? Look at the socket of the eye-stalk or the area around the "belt", there are areas which should be in shadow but aren't.

But yeah, it looks great.

And still probably better than I could do, so I'll shut up now.

• edited October 2017

@Triem23 it means a lot that you think mine is as good as the show

I'm still not 100% happy with the textures yet. The Dalek images you linked don't seem to have that dirty outline look to them. But, it looks good as is so I'll leave it

@JMcAllister I see what you mean. I'll double check, but it might just be the lighting and high diffuse reflectivity reflecting the lighting of the environment.

@JMcAllister are you referring to the Dalek's lights or the volumetrics of the scene? The scene ones are just messing around and I don't really like them either.