mapping help

[Erich]

Hello. I am trying to create a bottle label consisting of a gold graphic element on a square white background. The bottle itself has a displacement texture that I'd like to exclude from the label area. I have included a screen shot so you can see what I am trying to do.

I was able to apply the gold graphic to the bottle using a Corona decal, but am having difficulty getting the white background square behind it. My plan was to use another Corona decal for the background, hoping to remove the displacement effect through the decal properties. Unfortunately, I haven't been able to make that work. Is there a way to do this with corona decals, or is there a another, easier way to do this? I thought this would be a relatively simple thing to do, but all of my efforts have not brought about the intended results. Any help would be appreciated.

[Aram Avetisyan]

Hi,

I am not sure I exactly got what you wanted to have (a screenshot or image would help here) but from what you have described, I am sure that it is well possible to do with Corona decal.

If you want, share an image of what you want to get and the sample file, and I will help you out.

[romullus]

I was able to apply the gold graphic to the bottle using a Corona decal, but am having difficulty getting the white background square behind it. My plan was to use another Corona decal for the background, hoping to remove the displacement effect through the decal properties. Unfortunately, I haven't been able to make that work. Is there a way to do this with corona decals, or is there a another, easier way to do this? I thought this would be a relatively simple thing to do, but all of my efforts have not brought about the intended results. Any help would be appreciated.

If i understand correctly what you want, this should be possible to do with decals. Make sure second decal (the one with white square) has displacement enabled and add to base disabled. That way its displacement will override bottle's displacement and you should have knurling free area where you want.

Like always there are other methods to achieve what you want that does not require usage of decals, but if decals are working for you, i see no reason not to use them.

[Erich]

I was able to apply the gold graphic to the bottle using a Corona decal, but am having difficulty getting the white background square behind it. My plan was to use another Corona decal for the background, hoping to remove the displacement effect through the decal properties. Unfortunately, I haven't been able to make that work. Is there a way to do this with corona decals, or is there a another, easier way to do this? I thought this would be a relatively simple thing to do, but all of my efforts have not brought about the intended results. Any help would be appreciated.

If i understand correctly what you want, this should be possible to do with decals. Make sure second decal (the one with white square) has displacement enabled and add to base disabled. That way its displacement will override bottle's displacement and you should have knurling free area where you want.

Like always there are other methods to achieve what you want that does not require usage of decals, but if decals are working for you, i see no reason not to use them.

Thanks Romullus. That helped. Also, I found it it is important to place the decal objects in the right order! The reason I wanted to use Corona Decals is that it provides a very easy and fast way to change out the label or to make changes to the color of the label (and in this case, the background label). I decided to use a black, or no background, instead of the white as I think it shows off the logo and text better. I have attached some images to show this versatility.

But I am curious as to what other methods you would recommend.

[Aram Avetisyan]

Note that you can even use Curved decals with Corona 12 Daily builds, which should be the real use case for you I believe.

Remember to back up your scenes though when opening them with experimental/daily builds.

[Erich]

Note that you can even use Curved decals with Corona 12 Daily builds, which should be the real use case for you I believe.

Remember to back up your scenes though when opening them with experimental/daily builds.

Thanks for letting me know. I think that will be a good addition. However, I will wait until it is officially released with Corona 12 (non-experimental)

[romullus]

I have attached some images to show this versatility.

Good effort. You may want to try to add gradient ramp to decal material's opacity or displacement channel to smooth out transition between knurled and smooth parts, it's kinda harsh now.

But I am curious as to what other methods you would recommend.

You can do all that without decals by combining several materials, or maps and use several mapping channels to control placement of different elements. It might not be as convenient to use as decals, but on the other hand it's much easier to export such asset to different applications.

[Erich]

Good effort. You may want to try to add gradient ramp to decal material's opacity or displacement channel to smooth out transition between knurled and smooth parts, it's kinda harsh now.

Thanks for that tip Romullus. That sounds like a great idea. I have actually used 3 decals on the bottle: 1) a clear glass decal to create an area slightly larger than the label which removes the displacement effect in and around the label, 2) a decal for the background (black) material and 3) a decal for the decal graphics. So I am assuming what you are suggesting is that I would add the gradient ramp to the 1st decal (the glass material which is removing the displacement of the bottle). I will give that a try.

You can do all that without decals by combining several materials, or maps and use several mapping channels to control placement of different elements. It might not be as convenient to use as decals, but on the other hand it's much easier to export such asset to different applications.

I would love to see how that could be done, however, I am still relatively new to Corona. Can you recommend a tutorial that shows how I could do all that, or tell me which mapping channels you would use to achieve this effect?

[Erich]

You can do all that without decals by combining several materials, or maps and use several mapping channels to control placement of different elements. It might not be as convenient to use as decals, but on the other hand it's much easier to export such asset to different applications.

I was able to figure out a way to do create the area of the glass that had the displacement removed without using decals. However, I still couldn't find a way to add the actual label graphic. So I am still using the decal object for this. However, I now have another issue. I cannot get the label to display correctly. The material color I am using on the decal object (gold) is not showing up on the label. It worked fine with my previous method and as far as I can see I am using the same settings as before. I have attached a screen shot. All the text and graphics in the label should be a gold color as this is what I am using on the decal object. You can see the letter "Y" does have some gold on it, but for some reason all the other letters are black. I am really confused as to why this is happening.

The other issue I am having is if I use a black background for the label, it reflects into the liquid object inside the glass bottle. How do I prevent this from happening?

I have also included an archive of the scene. Any help would be greatly appreciated.

[Erich]

So, I changed the material a bit (see screenshot). I was able to finally get the gold color on the label that I was looking for. However, now, I am unsure about how to make the background immediate behind the label appear black instead of just clear. It should look like the image showing the black background but with nice gold graphics and text. Seems like I can only have one or the other (gold graphics and text with a clear background, or black background but no gold text). I am sure there is a way to do this, but I just can't seem to figure out is missing.

[romullus]

Hmm, it looks like there are some issues with this setup indeed. Corona to this day have troubles with handling complex refractive materials, so it's best to keep it simple to avoid potential issues. I made your glass and label with single material and decal should be working correctly now. You will probably need to fix your UV mapping, or masks, since there are some spillovers here and there, but i think you should be able to handle that on your own.

[Erich]

Hmm, it looks like there are some issues with this setup indeed. Corona to this day have troubles with handling complex refractive materials, so it's best to keep it simple to avoid potential issues. I made your glass and label with single material and decal should be working correctly now. You will probably need to fix your UV mapping, or masks, since there are some spillovers here and there, but i think you should be able to handle that on your own.

Hi Romullus,

Thank you for taking the time to look into this. Yeah, Corona definitely has it quirks, especially when using it outside of the archviv space. Unfortunately, I have not found a lot of resources for people using Corona for product renders, and since Corona was mainly developed for archviz work, I am finding it difficult to use for projects like this.

That being said, I truly appreciate your effort and the solution you provided. Your setup is very similar to mine, with the exception of the label and glass roughness additions in the glass base roughness slot. I'm curious about their function – removing them doesn't seem to affect anything visually beyond making the black background darker. Would you be willing to share your thought process behind including them?

On another note, with this method, it seems there's no way to adjust the size of the black background itself. Ideally, I'd like it to be slightly smaller on all sides than the surrounding non-displaced glass, creating a thin border of clear glass around the black label. Is there a way to achieve this effect?

Also, I would like to add a texture to the black background label to give it a more realistic look. However, I suspect I'd need to use a completely different material, like a black paper texture bitmap, to replace the flat black I'm using now. But if I plug a texture like that into the refraction slot of the glass material (replacing the current bitmap), I'm unsure if the paper texture would actually show through in the render.  Any suggestions on how to achieve a textured black label?

[romullus]

Your setup is very similar to mine, with the exception of the label and glass roughness additions in the glass base roughness slot. I'm curious about their function – removing them doesn't seem to affect anything visually beyond making the black background darker. Would you be willing to share your thought process behind including them?

My aim was to alter your setup as little as possible, just enough to make label work with decal. To be honest i would setup everything completely differently, but i didn't want to mess up your workflow and also i don't have much time to invest for this. As for the purpose of the mix map, it's there to enable separate controls for glass and label roughness. I named Corona color nodes accordingly, you can adjust them if you want to change the roughness of said elements.

I will try to to answer your other questions tomorrow or sometime later, it's late night here and i'm desperately lacking good sleep.

[Erich]

Your setup is very similar to mine, with the exception of the label and glass roughness additions in the glass base roughness slot. I'm curious about their function – removing them doesn't seem to affect anything visually beyond making the black background darker. Would you be willing to share your thought process behind including them?

My aim was to alter your setup as little as possible, just enough to make label work with decal. To be honest i would setup everything completely differently, but i didn't want to mess up your workflow and also i don't have much time to invest for this. As for the purpose of the mix map, it's there to enable separate controls for glass and label roughness. I named Corona color nodes accordingly, you can adjust them if you want to change the roughness of said elements.

I will try to to answer your other questions tomorrow or sometime later, it's late night here and i'm desperately lacking good sleep.

Hi Romullus,

Thanks so much for your help so far, I truly appreciate your assistance. Initially, I went with Corona decals because they seemed like the simplest way to achieve the results I wanted. However, as you pointed out, there's likely a more effective approach.

If you have some spare time and wouldn't mind, I'd be incredibly grateful for detailed instructions on how you would tackle this project.

As a Corona beginner, this project has been quite the time-consuming and frustrating experience. There seems to be a scarcity of tutorials specific to this type of work, and I find the Corona documentation lacking in detailed, relevant examples. This has left me scouring YouTube and forums for answers. While the Corona forum community has been fantastic and helpful, finding solutions to specific learning hurdles has been extremely time consuming. There's a definite need for more tutorials and resources geared towards those new to product visualization with Corona.

Again, if your willing, I would be extremely grateful for any help you can provide (even if its just pointing me to a relevant tutorial).

Thanks again for your time and support.

[Erich]

I have been doing some more work on this issue and thought I would post an update. I have been able to get the displacement and label graphics to work as I need, but still struggling with the black, textured background that is supposed to go directly behind the bottle graphics. It also needs to be slightly smaller in size so as to fit within the area without the displacement and leave a small margin of clear glass all around the label. I have attached a new 3ds Max scene file.

Any help would be greatly appreciated.