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newbie questions about rendering

ZBrush Usage Questions
#1

I’m trying to render a model of a girl sitting on a rock. I’ve got the lights set up to my satisfaction and am now trying to render her. I am facing four problems:

  1. I’ve turned antialiasing up to max on border and amount, but the internal and external edges are seriously jagged
  2. When it renders, it turns my rock and the figure’s hair solid black most of the time. The subtools and tools are then just shadows.
  3. When it does render properly, the fibermesh hair looks like brown string with no proper lighting. I’ve used the fibermesh that looks like silky hair in the preview.
  4. My figure does not cast a shadow on the rock when rendered, even though my primary light source shadow is set to 100%.

I would be so grateful if anyone is willing to help with any of these issues. I’ve read the documentation and watched the tutorials, but I must be missing the answers. :confused:

#2

pics or it didn’t happen.

Seriously though, type it up or images of your settings, and what you’re actually getting would help a ton.

#3

Sorry, I didn’t want to write a book on details and lose people at the start because they had to wade through my explanation. Thank you for asking.

I’ve answered most of the questions myself, because I exported the render and the results were a tiny little figure about 50px wide. No amount of antialiasing will smooth that out. I have to go back and try and understand the documentation on this and how to increase the size of my model. I’ve read and reread it, but it is very difficult to understand what I need to do. I upped the document size but it didn’t alter the size of the figure on export.

My figure is an imported .obj from DAZ3D. If I export her as a .jpg from DAZ then she is quite large. I don’t know why she is importing so small in zB. (I realise that importing a ready made figure to use is not done in the 3D world, but I am actually a fine artist and I am creating models to paint on canvas in the traditional way. I am tired of struggling to find the right life models, settings, costumes and weather in the real world, especially for surrealist paintings.)

I think the size of the model may also explain the hair looking like string, because each strand will be very large relative to the head.

The only one I can’t explain is why rendering sometimes causes the stuff created in zB to turn flat black and then all my subtools and related tools to do the same. I will try and replicate it and post an image.

#4

Some screenshots would definitely help to see what you have going on. A picture is worth a thousand words. :wink:

If your objective is to end up with an image that you can reference for painting, using the BPR render should get you what you need.

I’m not sure what you mean by “I exported the render and the results were a tiny little figure about 50px wide.” :confused:
How are you “exporting the render”?
The model size should not really have anything to do with the render/image size.

To export a render, you can go to Render > BPR RenderPass
and just click on the “Shaded” button. This will save an image that is the same dimensions as your workspace viewport.
The advantage of this method is that is separates various components of the render- like shadows, mask, etc. which you would need to combine in Photoshop. The image should be the same dimensions as your document window.

Alternatively, after rendering, you can go to Document > Export
This should also export an image the same dimensions as your viewport (I’m sure your document window is not 50px wide!).
The advantage of this method, is that it exports a flattened image of your render - including background, shadows, etc.

The blackness sounds like you may have some texture/material issues… or perhaps you might have some masks enabled on some of your subtools.

On a stock DAZ figure, I don’t need to do anything (no resizing of the model) to get rid of jaggies - there are none in my BPRs.
In Render > BPR RenderPass > SPix, I have it set to 3 as my default.

There are many other settings that can have an effect on your results, but if you don’t stray too far from the ZBrush defaults, you should get pretty good results for your renders.

#5

Thanks for answering Thor. By exporting my render I mean that I do a best render and then export the resulting image. I’ve been experimenting with it and I think that has to do with the order in which I was doing things. I tried increasing the size of my document and then importing my tool and placing it on the canvas and when I did a best render and exported it came out larger and the jaggies were gone.

I don’t know what I’m doing wrong but I keep getting really weird results. When I do a best render it changes the colour of my fibermesh hair and makes my figure look like it is coated in plastic. The fill colour on this model was blonde. As soon as I rendered it turned black and the skin looked as if it had been varnished. It also creates a new palette of shiny materials and all the other materials have disappeared. Below is a screen shot. My base material for my figure and the stone is chalk, because I don’t want a shiny material with oily highlights.

I used append to sit my figure on my rock, and I notice that the rock does not appear in my tools or subtools even though it appears on the canvas. Things keep appearing and disappearing and I don’t know why.

grab.jpg
grab.jpg1719×1173 233 KB
grab2.jpg

#6

Oh, and I don’t have any masking on anything.

#7

My figure and rock looked just fine until I started setting up the lights. I followed the instructions in the tutorial video and switched off the main light then went to LightCap and created a new light. At that point my rock and the fibermesh hair changed colour and both became dark metallic. All the materials apart from those shown above then disappeared. I am so confused!grab3.jpg

#8

See top statement on this page >> http://docs.pixologic.com/reference-guide/material/matcap-maker/
Your material plays into this.

#9

I don’t understand, Doug. Sorry! I thought clay wasn’t a metcap material. Why does it only have an effect when I start using the lights? How does it play into what is happening and how can I stop it? Sorry to ask all these questions, but I am going round and round in circles. Each time it does this to my model it permanently changes its appearance. I really appreciate your help on this.:slight_smile:

#10

And now the render where hair and rock become a black hole!

grab4.jpg

#11

Once I have applied the lights and got these strange effects, creating a new document does not restore the materials palette. If I create a new instance of a tool, for example the head from tools, it is created in one of the limited materials available. I have to quit zB and relaunch it to regain my full palette.

#12

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

#13

Thank you, Doug! I knew there was something missing from the tutorial video. It is the bit about needing to use the colour palette to fill the figure first so you bake in the colour. I’ll have to go back to the beginning and start again. I was not doing this step, so maybe that is why I wasn’t getting the expected shadows etc. I’m sorry to blast all these questions out, but it is really difficult to bring the different strings together and make a coherent process out of it. You miss one step, and it just doesn’t work.

I still don’t understand why the fibermesh behaves the way it does, though. It changes colour when rendered. I also can’t do the things shown in the tutorial, like changing the base and tip colour, or using the grooming brushes to paint tips, middle or roots.

#14

Doug, I’m sorry to say that I am still facing the same issue. I took my figure imported from a .obj file and used color>fill object to bake in the colour. I then used chalk and a flesh tone to paint my figure in MRGB mode. I then turne don my lights to check what happens and I got what looks like a plastic coated bronze figure. Those were literally all the steps I did. I keep reading the documentation over and over and I just don’t see why it is doing this. :cry:

I’ve done these steps so many times over I already know them off by heart. I just can’t get the results.

#15

As far as I know you must use BPR for fiber renderings. And you are using lightcaps for your lighting this overwrites your material settings. (The LightCap sub-palette is used to create a new LightCap™. LightCap is a way to create a Material or Matcap in real-time by manipulating directly the lights they simulate.) There are 2 light systems, 2 render engines and 2 material systems in Zbrush. Its still confusing for me after 3 years of Zbrushing.

#16

Wow! That is really good to know. I think this is the most complicated programme I have ever encountered. Knowing that really helps. Thank you so much!! :slight_smile: I will know what direction to look now.

#17

I’m now trying to light my model using lights and I have a couple of questions. I’ve read the documentation on lights, as opposed to lightcaps, but it is a bit sparse and the video tutorials only cover lightcaps. There is very little on teh web about using lights in zB4.

I’m using lights rather than lightcaps to get away from the problem I have been encountering with lightcaps making my model look like plastic metal.

Question 1: I’m trying to place a back light as my main source light, then three others as environment lights. The backlight has to be high intensity and the others low. I’m finding that any adjustments I make to one, change all the others to the same value. Also, the lights appear very different in preview than they do in render. In fact I can’t get the intensity of lighting I need with the backlight set at 100%. Is there a way to adjust the lights separately?

Question 2: When I set up the lights, it only lights the subtool I’m working on, and not the other subtools, such as hair and the rock my figure is sitting on. How do I get the lights to light everything in my scene?