ZBrushCentral

lights, materials, and rendering

ZBrush Usage Questions
#1

I have no doubt that zBrush is a very cool programme and I can see that people get amazing results, but I am just about ready to give up and ask for my money back.

I have looked at videos and read and reread the user guide until I am cross-eyed. I cannot find any simple, step by step explanation of how to use materials and lights together to get the effect I am looking for, nor of how to reset lights to the default setting. I have to quite out of the programme to get rid of the lights I have set up. The user guide is not clear on how these things work, and their section on lights as opposed to lightcaps, is very poor. Does anyone know of somewhere where there is a really good explanation of
(a) how to get material modifiers to work with a subtool? I have a figure with fibermesh hair, and when I try and modify the materials of the figure, all it does is modify the hair, even thought the figure is selected in the subtool palette.
(b) how lights and materials work together and what results you get by changing onto the other? How can I get rid of the effect of plastic coating on my model as soon as I add lights? I’ve tried using basic materials, but the effect is always the same.
© how to get lights to work with all the subtools together and not just the selected subtool? :cry:

#2

Select Best render, then play with your lights…

#3

Thanks Doug! But how do I get my lights to work with all my subtools? If I light one subtool the others are unaffected. And how do I add multiple lights at different intensities and distances? If I adjust one of my lights then all the others change their settings to the same value. LightCaps allows me to do it, but the straight lights don’t.

#4

http://docs.pixologic.com/user-guide/materials-lights-rendering/lights/
http://docs.pixologic.com/reference-guide/light/lights-type/

#5

I’ve read and reread that documentation at least 8 times, Doug. Nowhere in the documentation does it give answers to the questions I am asking. There is a fundamental gap between the information given in ‘Getting Started’ and that in the user guide — a failure to explain important details that someone just starting out needs to use in order to go beyond getting started. The documentation makes assumptions about knowledge an newbie doesn’t have.

#6

a) Turn on Mrgb than Colour-FillObject
b) http://www.youtube.com/watch?v=l2Juj2i77hU
http://www.youtube.com/watch?v=7W9KAph-4ms
http://www.youtube.com/watch?v=nIPpD21z3d8
http://www.digitaltutors.com/tutorial/3405-Materials-and-Rendering-in-ZBrush

c) No idea what you mean.

#7

(a) The most important thing to understand about materials is that all subtools will take on the selected material unless you have filled them with a different material. So if you select a material in the Material palette the chances are all your subtools will change including the selected subtool. For example:

  1. Load the DemoSoldier from the Lightbox>Project tab. You’ll see that theselected material is SkinShade4.
  2. Change the material to the MatCap Red Wax material. All the subtools will now show that material.
  3. The selected subtool will be the top one, the soldier’s body. We’ll fill it with the SkinShade4 material. First select the SkinShade4 material again (all the subtools will change back to showing that material).
  4. Now click the ‘M’ (Material Channel) button at the top of the UI (towards the middle). By turning this on we are telling ZBrush that we want to work with just materials. (You’ll see that to the left of the ‘M’ button are the ‘RGB’ and ‘MRGB’ buttons. These are for when we want to work with just color - RGB- or color & material together - MRGB.)
  5. Now press the FillObject button in the Color palette. The soldier’s body will go white. (Although we had the ‘M’ button selected this is because we hadn’t done any polypainting. If we had already painted the subtool, filling with the ‘M’ button on would mean we didn’t overwrite the color.)
  6. Select the MatCap Red Wax material again. This time the soldier’s body should remain white.

(b) The second important thing with materials is that MatCap materials have baked-in lighting. This means that they don’t react to the lights in the Light palette. If you want to work with materials and lights, stick to the materials in the lower part of the materials pop-up, or materials that don’t have ‘MatCap’ in their name. And for the time being, ignore LightCaps!

©The most likely reason that you were having problems is that you had a MatCap selected. If you continue to have problems then please post a screenshot so we can see what settings you are using.

#8

Thank you, Marcus! That is an exceptionally good explanation. I think the answer to my question c is that they are all separate subtools and being lit separately. I found a button called ‘merge visible’ in the subtools palette and once I’d merged them all, the light affected all parts of my model. I now only have to discover how to get the fibermesh to do what it says on the tin. If I change my base and tip colours, nothing happens. For the moment, however, that is the least of my worries. Thank you SO much for taking the time to explain.

#9

I’m glad you found the explanation helpful. :slight_smile:

I’m puzzled by your subtools reacting to light differently. It shouldn’t be necessary to merge them (in fact, with complex models that might not be possible). Are you using BPR to render? That is best for 3D models.

For FiberMesh, to get the best results from the Base and Tip colors, set the BColor & TColor sliders to 1, and the BCVar & TCVar sliders to 0. That will give you maximum color with no variations. Do a BPR render to view the results.

#10

I have a feeling I’ve clicked on so many buttons and fooled with so many things that I have no idea what I’ve done and that may be why I am getting the peculiar effects with lighting the subtools, Marcus. I have gone back and started again, consciously keeping to the steps I now understand.

I have tried a different approach with the fibermesh, by extracting the mask for the hair and then applying the fibermesh to that, using polygroups to style it. I tried your suggestion with the colour, but it still comes out dark brown, like the original fibers142. I haven’t try the colour brushes, yet, so maybe those will work. I’ve been using BPR because it seems to render realistic hair, whereas best makes the hair look like string. Is that wrong? I know it says in the user guide to use best for 2D work, but it doesn’t seem to give the same results.

If I still have the lighting issue, then I will post an image. And there I thought I’d made a discovery with the merge visible button :confused: There is so much to learn! Thank you again for taking the time to help. :slight_smile:

#11

Those are really, really helpful videos, Stone 3D. They actually explain it so well. :slight_smile: Thank you!

#12

“To evaluate your Fiber with complete shading, press the BPR button at the top right of the interface or use the Shift+R hotkey. This will render your FiberMesh so that you can be sure you’re happy with the results before proceeding to the sculpting and styling phase. Picking the right Material is also a key factor in your FiberMesh render.”

Excerpted from http://docs.pixologic.com/user-guide/3d-modeling/fibermesh/workflow/

#13

[QUOTE=Doug Jones;1067007]“To evaluate your Fiber with complete shading, press the BPR button at the top right of the interface or use the Shift+R hotkey. This will render your FiberMesh so that you can be sure you***8217;re happy with the results before proceeding to the sculpting and styling phase. Picking the right Material is also a key factor in your FiberMesh render.”

Thank you Doug! I think I’m coming unstuck on the order in which I am doing things.