Confused by an interview question regarding textures...

tgnsd

Yeah I know I lurk, so my post count is low. I usually don't have much to say.

BUT! Today I scored my first 3D interview as a texture painter. It was over skype so it wasn't all too professional. ANYWAYS, one of the questions that was asked:

Can you create a custom metal procedural and apply alpha or transparent overlays of additional maps to bring out "dough batter, flour," and other effects 'sprayed' or 'accidentally' dropped onto the mixer?

I'm confused as to why use an alpha on a texture..... why can't I just doctorate the diffuse texture I'm working on in photoshop to appear as if there is an overlay by using opacity and layer overlays? Then create the normal to appear as if there was just the slightest height difference between the two substances.....

I mean I could connect two separate files to the diffuse node and have one with an alpha so the second diffuse file will show through but isn't that wasting space?

Either way.... I got the art test file which I'll be completing later tonight, but as a student I'm curious as to how someone with more experience would have answered or looked at this question.

Thanks in advance for your replies.

SpeCter

I think he referred to alpha blending.It´s used to blend 2 textures into each other.Let´s say you have a grass texture and a stone texture and you are working on a terrain.
You fill it with the grass texture and then you want some areas which are made of stones.Now alpha blending comes into play.The black areas would be the grass and the white areas would be the stone and grey would be something inbetween so that the grass and the stone would blend into each other.
You could do that in photoshop if you wanted, but imagine you would do that with lots of terrains. It´s somewhat faster and easier to do that with alpha blending inside the editor.

divi

by painting it into the metal texture itself you'd have it show up everywhere if it would be tiled. by having it as a seperate texture there are various ways to have it show up only where you want it or change only the tiling of the flour etc.

if you know how to do it then just answer yes
it requires more ressources compared to just adding it into the diffuse but also allows for more variety.

SpeCter

There is a second method call Vertex Blending which does the same but doesn´t use a seperate alpha but the vertex color information for blending textures.

Both used often to break up repetition in your textures and making them more interresting.

(If i said something which was obviously wrong feel free to correct me and kill me afterwards :P )

Xoliul

You can combine an alpha and vertex colors, Specter, this is actually prefered due to better visual quality and is used extensively in Uncharted 2.

SpeCter

Thanks Xoliul, didn´t know that you actually can combine them at all.Before i didn´t even think that it made any sense, but thinking about it made the advantage obvious to me.
If i have time i will try that out, sounds interresting

Justin Meisse

wow, that's an oddly worded question.

renderhjs

I noticed that some studios often invented their own words for usually common things like Id software that used another word for normal maps, or some of the other similar threads like these where people that were interviewed were introduced to some new words. I remember a post like that were a Texture Atlas was asked about but with a odd word and upon googling I found that word on that company website - seemed to be standard for them except people here at Polycount never heard of it. That person asking here was confused just as much as you.
I guess if you are that tight working in the industry you don't have the time to always catch up with other cultures - like terminology of recent developments.
In case just ask and verify what they sometimes mean because these guys usually work already in a well oiled team and they might end up sometimes with their own terminology.

Illusions

tgnsd wrote: »

I'm confused as to why use an alpha on a texture..... why can't I just doctorate the diffuse texture I'm working on in photoshop to appear as if there is an overlay by using opacity and layer overlays?

The key word in their question is that the texture/shader is procedural. I did something similar to this for my previous job, except instead of a procedural metal shader with dough or flour on it, it was metal with ice forming on it. In Maya it was essentially a layered shader, with a procedural metal shader on the bottom, and a procedural frost shader at the top. How much frost was present was done by controlling the alpha channel or transparency on the frost shader through an attribute control.

It might be that they don't want you to paint the texture as a whole because it might not be static. The procedural shader I made with frost and metal was animated, and had controls for such. We'd also do stuff similar to this if we had to animate disease spreading, tissue death, or other things where certain areas of an object had to show a vastly different look from what it was originally, and also possibly animate that new look, or move it to a different area on the mesh in the future.

Autocon

Very oddly wordered question indeed.

I also got one of those very convaluded questions asked once during a interview. I had no clue what they were trying to ask me so I had to ask them about 3 questions to find out what they actually ment by the question. Cant remember exactly what it was but it dealt with if your Difuse texture is too dark and the problems you will have with lighting.

As soon as I figured out what they wanted it was easy, the goofy wording of the question is what made it diffucult to answer.