This turtle rocks

[ViennaLinux]

This is my first ZBrush model I've made.
I have to say that this app is simply amazing. The highres model in ZBrush is 2.2 Mio polys but I exported a 138.000 poly version and a 4096x4096 normalmap and colormap.

In Blender ambiant occ. looked so plastic and unreal - thank god there is indigo.
Here is my quick and dirty wip render.


ToDo:
- lower the normalmap value
- lower the phone exponent to 20 or so
- place the turtle a little bit to the right.
- apply a nice sand texture

There are 2 options:
- an underwater scene like "lost buddha"
- an on the beach version like the above with some shells or so.

i prefer under water because I also wanted to rule the world with some nice caustics ^^ - lol

[ViennaLinux]

I changed a lot of things but at the moment I'm failing to get a water with caustics.

here is my progress so far .. good night.

[Kram1032]

Nice!
Show us, what you tried to get underwater caustics and we might be able to help

[ViennaLinux]

first of all: thank you for replying Kram
second: why can't we chat in icq? you never replied - did you set me on your ignore list?

I figured out what the problem was - I forgot that blenders texture to disp. does of course not work when exporting to indigo. so i need to apply all modifications first.

1) I still need to get my normal map into a bump map - whats the best way
2) Using phong as a material does not look right but using diffuse does look very strange because color saturation seems a lot higher. What IOR and Exp. would you suggest?
3) What material will give me caustics without raising render times a lot? transparent + sss but with SSS turned off?

[BbB]

Hi ViennaLux,
Just got your message. I haven't tried exporting normal maps out of ZBrush (normal map exporting was broken in 3.0, perhaps it's been fixed in 3.1 but I haven't tried). As far as I understand, the displacement map (16 bit tif) includes the same info as the normal map - which people use mainly to fake displacement on very low-poly models in game engines.
What I do is what you did (I think), i.e. exporting the displacement map, convert it to an 8-bit RGB jpg, and plugging it into the bump channel in Indigo.
Of course, this is never going to be as good as displacement, but it works ok provided that 1) you export a relatively high-poly level of your mesh (level 3 or 4, which for me works at 200,000-400,000 polys per mesh) and 2) you export a 4k displacement map (4096x4096 pixels).
My specular maps are handmade. For skin, I generally use a mixture of the displacement map (with super-boosted contrast) and a desaturated version of my colour texture mixed in Photoshop at 50 per cent.
The key to get the specular map (actually the exponent map) to do anything in Indigo lies in playing with the gamma value. A higher gamma will increase the contrast of your image and therefore the variation in exponent. The B and C values (again as far I understand them) will determine the max and min exponents depending on the black-and-white value of the maps. I could try to post a few examples if this is not very clear.
EDIT: on your mat question. I'd definitely use a phong on this. Which will give you nicer bump and speculars. For the shell I'd say on the top of my head something like IOR 1.2-1.3 and Exponent of 30-60.
B

[ViennaLinux]

Thank you for your great post BbB. I just saw that you speak german too


So what you mean is that i should export a disp map with 4K and then in PS convert it to a 8 bit/channel image. then put it into indigos bump slot.

uh and normal maps are back in ZBrush 3.1 but there is a very anoying bug that Ctrl + S for saving crashes ZBrush - so you always have to go with you mouse up to "Save Tool" and not use the shortcut. Took me 2 days to find out that this is not my fault So crazy that they release the version 3.1 with this major bug in it.

[BbB]

So what you mean is that i should export a disp map with 4K and then in PS convert it to a 8 bit/channel image. then put it into indigos bump slot.

That's right. At least that's what I'm doing while I wait for displacement. I guess that even if we got displacement, I might still do that in some cases as it would render faster. In my engineer piece, the face has about 200,000 polys but enough detail that it wouldn't necessarily need displacement.

[Kram1032]

Why do you convert to 8bit jpg?
Indigo can read 16bit png!

To the ICQ part: Oh well... I nearly never use ICQ ^^ I didn't ignore you but I didn't see that you said anything, there... as it's never open

[BbB]

Indigo can read 16bit png

Can it? I thought that posed all sorts of problems!

[ViennaLinux]

@ Kram - what messengers do you use? msn .. jabber .. irc?

Progress report.
-) I added a bumpmap for the sand
-) I exported a 4K dispmap out of zbrush and mapped it to the bumpmap slot in indigo.

One weird thing and i have no idea why (yet):
-) Why is the bump map only applied to the one half of my turtle? the bump map is the same size as the albedo and both look right in Irfanview. I will try to use 8 bit png instead of 16.

[Kram1032]

I think so, yes... The limitation is, that you can't use single-channelled textures... (greyscale)
They need to be RGB or RGBA 8 or 16 bit per channel....

@ViennaLinux:
Yes, never heard, yes. But I'm not the most frequent user of any messager...
Currently, MSN is good... two weeks or so ago, you found me more on IRC... Sometimes, you only find me here

But what's now with the water?

[ViennaLinux]

So i tested now single channel 8 bit grayscale png and it failed too .. here is what it looks like:


Water --> delayed because that will raise rendering times and i want to have everything done before I have to wait 30 mins for a preview *g*

[psor]

@ViennaLinux

AFAIK ... it's a "No, No" to use greyscale maps at all! So convert your map
to greyscale and then back to RGB. You could also just use a "desaturate"
on the image ...

edit: Just to make sure. Save the image as 8bit RGB! ;o))




take care
psor

[Kram1032]

16bit always is better than 8bit...

[psor]

If someone can confirm to 100%, Nik?, ... that 16bit is supported, then of
course you can go with 16bit, if you take care of the RAM usage. ;o))

And on a side note I would say, it's not always better to use 16bit, because it
depends on your needs. If you've a gradient where 8bit could cause banding
then yes it's good to use 16bit. If you've a rather "normal" 8bit diffuse map, I
don't see a need for 16bit texture ... that would be as if you would use a
4096x4096 map on a 1024x768 rendering.

nb: As I said, it depends on your need.



take care
psor