3D Questions and Answers

Idea: To give generic and sometimes specific answers to 3D questions. Ask us anything 3D related and we'll answer. Other blog: @3Dhelper on Twitter and Mastadon

[3dhelp]

Hey! A lot of us are moving to different social platforms soon and I would like to know if you have a Twitter or insta? Thank you for taking time to read this!

Hi! yes, you can find me at https://twitter.com/3Dhelper. And if I can get my Mastadon account approved, I’ll be on there too with the same name. 3Dhelper. 

[3dhelp]

Tip Time Tuesday: Questions?

Have a question about something you’ve seen but you’re too scared about contacting the artist about their work? Thinking ‘What if’ can sometimes be very destructive.

What if they respond? What if they do want to help?

What do you have to lose? It can’t hurt to ask politely. Right?

[3dhelp]

Tip Time Tuesday: Personal

You are your own biggest critic (for good reason). 

But don’t reject other people’s compliments. Take them and remember to compliment yourself on a job well done. 

Accept your level, see where you’ve come from and where you’re going. 

You’ve got this. 

You’re constantly improving!

[zbrush-tips-n-tricks-blog]

Gradients aren’t always your friends. Sometimes they make the canvas to be uclear. It’s harder to notice some errors on your models.

[3dhelp]

Tip Time Tuesday

Have a 'You day'. Maybe take a long hot bath, or read a book with a non/alcoholic drink, or go out and have a hike. Hang out with a loved one, go shopping, watch a movie, have a date with yourself.

Whatever you like to do besides work/art/writing/sitting, do that for a day or a night. Get recharged. Get inspired. And don’t ever feel guilty about it.

[danny-mac]

60 Second Tutorials

Just curious, are you guys interested in seeing more quick tutorials like this? :) 

[3dhelp]

Danny has amazing 60-second tutorials. I highly suggest you watch them if you’re interested in 3D sculpting in Zbrush. They’ll make your life much easier. They’ve made my experience with Zbrush 2018 all that smoother.

[zbrush-tips-n-tricks-blog]

Quicksave maye make a lot of troubles! How to prevent hem?

[3dhelp]

Save.

Just a reminder. Save your work!

[3dhelp]

Tip Time Tuesday

Find scripts for your program. Use them. 

It will save you time and will lead you to a smarter way to work. 

[kasiaslupecka]

This week I’ve prepared some tips for everyone who is confused with arms. I know that pronation and supination is confusing and I recommend to learn in by heart <3

I have also announcement!

The day is approaching when I will release ebook or Gumroad PDF with all my anatomy tips + additional lessons + commentary.

I still am thinking how I will publish this but it will be done. Anyone who’s interested finally will be able to get everything in one place and some more good content. I will post some dates soon so look for that in next few weeks !

instagram.com/manequim_art

twitter.com/KasiaSlupecka

[3dhelp]

Not really 3D but I thought it would help someone.

[3dhelp]

Tip Time Tuesday!

Textures do not need to be squares (they can be rectangular if that fits better) but they always follow the power of 2.

If not, the computer will buff out the texture and make it fit which will waste good texture space for other items. See visual example below.

The large square counts for 2048 pixels of memory available for a hypothetical game. The purple boxes are textures not following the power of 2 ratio.

Some games don’t even use textures the traditional way:

 http://polycount.com/discussion/155894/decal-technique-from-star-citizen

http://twvideo01.ubm-us.net/o1/vault/gdc2015/presentations/Brown_Alistair_VisualEffectsIn.pdf

[3dhelp]

hey! i heard it's good to have as few separate pieces as possible in your UV maps since it will supposedly save memory. is it better to have few separate pieces or a more compact UV map with little emtpy space?

Good question!

The answer really depends on what you’re working on. This has been covered in this polycount thread quite well but I’ll paraphrase. (Long post ahead)

If you’re thinking of going with a single map like I usually do for low draw calls in small mobile games, the main things to think about are seams, distortion and spacing. 

A good UV map should be easy enough to interpret without the model which means logical seams, have enough space between shells for pixel bleed (having some unused space in the map is almost inevitable)and has minimal distortion.

Example: Character UV (below). The unwrap is easy enough to read, uses up the most space it can. Has a bigger uv for the face for the most detail, and in this case doesn’t have overlapping UVs - although here’s a link about it being totally acceptable to do. 

Nowadays we don’t need to worry too much about blatantly visible UV seams thanks to programs like substance painter and blender allowing us to paint diffuse maps on the models themselves. However we do still need to be smart about the unwrapping as a whole. 

Large shells usually mean less seams and less seams mean it’s easier to read what the map shows. Finding where the character’s legs are compared to their arms to add a graze or a freckle can be a 5 second job or a 5 minute job with multiple programs open depending on the layout of the character’s UV map.  If you’re on a tight schedule an easy to read map is a must.

“ UV Shells are UV islands. When you unwrap a model, you usually 'break it up' in smaller pieces (unwrap modifier). [These] unwrapped pieces are UV shells (or islands) “

- Zbuffer

Hidden seams are definitely going to be a benefit when planning out UV shells. Normal maps can sometimes distort along the seams when baking in some programs but that’s a whole other kettle of fish. Just know that UV seams are going to be a big part of baking, if you’re doing that. And most people like to put seams on hard edges and where clothing seams usually are.

See here for a good forum post on UV seams and Normal Maps. 

Distortions in the UV map that are extreme will likely result in smeared pixels. Obviously this will affect how sharp the texture map looks on the model itself. “Relaxing” the UVs usually takes care of this in your chosen 3d program.

UV mapping grids like the one below can really help visualize the distortions that are being made by the UVs. 

Spacing and pixel bleed has been covered really well here it’s definitely something to keep in mind. I suggest a little plug in from Flaming Pear called solidify to help with this. It clamps the textures in Photoshop. I highly recommend deleting any colours you have in the free space around the UV shells. 

Paul H. Paulino has made an excellent article on their website for texture mapping tips, you can visit his page here

So, in some cases UVs can be spread over several maps. See this video. The guys from Flipped Normals explain that to paint high detail (say for VFX), you’ll need a ridiculously high pixel texture map so the solution to not killing your cpu while opening the project is to separate the UVs into UDIMs. (I highly recommend their videos)

“ UDIM stands for U-Dimension. UDIM is a way of creating a single linear number that identifies each integer block in UV space. You do this by defining a limit on the number of patches you can use in the U direction (the U-DIM) and then resetting U to 0 and incrementing V by one after reaching that number “

- fxguide

This is also pretty useful for different materials: e.g wood goes in map 1, glass goes into map 2, stone goes into map 3, etc. I personally don’t have a need to do this for every project but it’s something that a lot of people do.

Example image from Allegorithmic’s help page

As you can see in the above image, the spacing between the UV shells are optimized with the ‘gun’ and ‘legs’ UDIMs leaving very little space between shells.

Also see Texture Atlas/Decal sheet/packed texture 

I hope this helped answer your question :)

[3dhelp]

Tip Time Tuesday!

A texture map with minimal spacing will save on memory and it will give optimal space for texture data. 

So play a few games of Tetris before you pack your UVs!

[3dhelp]

Tip Time Tuesday! Rigs

Reset X-Form/Delete History before rigging. Make sure you have a clean mesh. 

[3dhelp]

Tip Time Tuesday! 3D

Make sure your models are centred (0,0,0) to the world before exporting or rigging. 

[3dhelp]

Tip Time Tuesday! 3D modelling

It’s easier to model from a lower polycount to a higher polycount than the other way around.

[3dhelp]

Tip Time Tuesday! Art Rules

There is always an exception to the rules. But first, learn the rules.