UV Unwrap Canvas Density?

[Cory-Dubeau]

Hello everyone,

I apologize if this is a rudimentary question, or if it has been answered here before (I checked most threads for this), but this is driving me *-crazy-* and I needed to know if there's an easy way to resolve this.

I have finally undertaken the task of not just using seamless textures with a standard UVW Box Map, but 3DS's more precise UV Unwrap modifier to hopefully achieve for more precise (and crisp) results.

My problem, simply put is that the UV Unwrap modifier seems to be inconsistent with how it scales it's 0-1 UV canvas, per object, and I would like (if possible) to increase the map density while keeping the mesh within the confines of the UV canvas so that I can effectively output a UV canvas to Photoshop for some texture fitting. Allow me to give you an example that has had me scratching my head all day.

As you can see below, I successfully unwrapped a simple timber column and was able to composite a wonderful Photoshop texture right back on to it with stunning resolution (I actually got giddy doing this- especially since the rendering times were significantly shorter than my usual composite map renders!):

Given my (relative) success, I decided to repeat this technique, but with a few more instances of geometry to save time and precious sanity. This was attempted with some exposed rafters and found that, despite the canvas and UV template maps being the same size, the texture performance (despite me providing a 4096x4096 @ 300 dpi) map, I received poor viewport and rendering performance:

I then questioned if my map was too small as I had an overkill 2K map on a single object vs. a 4k map on several objects. After watching a few videos on the subject, I discovered a handy little plugin called "TexTools" to view my UV scale (as a checkerboard) to gain a sense of the UV scale for my object, and what I got was surprising:

It seems the density of each object is significantly lower-- likely because there are more objects to cover in the same UV canvas. Despite what I learned from other videos no matter how I packed my UV's or AI upscaled my Diffuse map from Photoshop (I stopped at 8K with similar results), the only thing that reduced the density of my UV's was to overscale the mesh outside of the 0-1 UV canvas, but then you need to rework your UV Template as the meshes have moved (EDIT: you can't render the UV Template as nothing is within the 0-1 space..).

So to summarize, is there a way to increase the relative scale of UV intensity within this canvas, or am I best to work on a smaller set of objects, as with the column above and bake them all down at a later stage?

Please pardon me if this is a rudimentary question, I am quite new to unwrapping but find the results highly rewarding and want to improve my craft as a arch. visualizer. 🙂 

Thank you all in advance for your help with this, and sorry to.. "wrap" you up in this- I am hoping it's a relatively simple (for 3DS standards) fix!

Cory, the apologetic. 

[Diffus3d]

Hello @Cory-Dubeau ,

4096 x 4096 @ 300dpi is equal to 983 x 983 @ 72dpi which is what monitors use.  So, you want 4096 x 4096 @ 72dpi here most likely.  The post is pretty long so maybe I'm missing something, but that's the first problem right there.  Start with that and probably the problem is resolved.  

Best Regards,

[Cory-Dubeau]

Hello @Diffus3d ! 

Thank you for your help. I always imagined that higher DPI maps would often result in sharper textures, are you saying that 3DS natively supports 72 DPI and therefore scales down the 4K @ 300 DPI maps? 

I just find it strange as I go to change the DPI in Photoshop, it takes the reference image of 72 DPI and wants to "proportionally match" what was there by scaling everything by a factor of 416.65% (never really understood this part).

Usually, I just reset the pixel dimensions back to their default 100% to increase pixel density (this works well when exporting bump maps and detailed reflection color maps).

I can give this a shot later today to see if anything changes. Perhaps following in Photoshop's footsteps, I can export this map at 8533x8533 @ 72DPI since the file size is equivalent.

I'm all ears if you have any other ideas! (I also stumbled upon another feature of the UV unwrapper that allows multiple tiles. Would you recommend this for larger sets of objects to wrap?

Appreciatively,

Cory

[CiroCardoso3v]

I would recommend you to explore the use of UDIMs. That is what use when I need to texture large areas

https://www.youtube.com/watch?v=DmuHLe6MjEA

I am not sure if Photoshop is going to help you with that, so you probably also want to check something like Substance Painter or even Mari (has a free version) to do this kind of work.

[Diffus3d]

Hello @Cory-Dubeau ,

8k textures for some wood is overkill most likely.  You might be under the impression that more resolution means more quality but that's not always the case.  The lighting itself will add details based on your bumps and smoothness maps that is outside the texture itself.  I would make them 4k maps @ 72dpi and see how it looks.  But remember, you don't need more res than whatever your display device is capable of displaying at a specific size on screen.   As far as UDIM, I don't use it much so I'm not the best person to suggest there.  I will agree that substance painter is 1000x better than Photoshop though.  I don't even use Photoshop anymore outside of tone mapping EXR's, and even that I'm starting to use Affinity more and more.  

Best Regards,

[Cory-Dubeau]

Hello everyone!

My apologies for the delay in response (the week got the best of me), I have not heard of UDMI's as of yet, but I suspect that is likely what 3Dio's Scene Wrapper utility uses to map out the points of interior scenes. What I gathered from UDMI's is that 3DS (since 2017) seems to support a vast array of these, and all I need is the right material assignment, so I must give this a try. 🙂

In addition to all the above, I have heard heard things about Substance and it's interoperable with 3DS's material editor- the last thing I need to check is if I can assign Corona sub-materials for it. If so, hello selectively-detailed UVW's 🙂

[Diffus3d]

Substance is operable with all render workflows, the exporting of the resulting textures has presets for every major renderer.  Maybe at one point that was true, but the modern version works with everything and if there isn't a pre-made preset for Corona (there is, I checked) you can always make your own.  Best of luck!

Best Regards,