Apply image to Flat Disc not working

Unity Engine
1

Hi,

I am trying to apply a image / texture to a flat disc - (Sphere with Z axis=0)
It only shows part of the image?

I have tried making the image smaller and the disc larger but nothing works.
All I want to do is see the whole image on the flat disc but only can see a small portion. Do I need to scale the image or use UV mapping?

Any help greatly appreciated. :idea:

2

you need to sort that out in your 3d modelling application. UV Map the texture to fit correctly there and Unity will comply…

3

Many Thanks,

I gather I can create a Disc shape in Blender3D, then apply my image so that it looks correct and then ask blender to create a UV Map, then export the whole object into unity. Would that be the correct way to do the UV Mapping?

4

Hi, I’m not a Blender user, but that sounds right to me - give it a go!

5

I have just downloaded Blender3D and must say that it looks rather complicated to msay the least, and i have no idea where to start.

I am very new to 3D modelling, and am struggling with it.

What program do you use?
How would you do it in your program?

6

Well, I don’t do loads of 3d modelling myself, but I can usually manage to get what I need from my copy of Carrara Pro.

Tell you what, if this is all you need and you want to give me the specifics, I’ll knock something up for you if you like?

Does it have to be a squashed sphere (is that really what you want)? or are you after a very short cylinder (so you have a flat top)?

Another alternative for you could be to use just a small plain (a square) with a texture on it that has a circle (with transparent surrounding)?

just a thought.

R.

7

Thanks thats really kind of you and would be really useful.

Your absolutely right, I believe I do need a flat Cylinder and not a squshed sphere, as the visible part needs to be flat. Its just a flat circle really.

What do you require from me in order to correctly position the image on the flat cylinder?

P.S. If I did create a flat square with the texture applied and placed a transparent circle ontop of it, would I be able to “Fix” the underlying part of the image onto the circle in order to be able to rotate the transparent circle with the underlying part of the image still attached?

8

OK, here’s your Disc, hit ‘Download’ below for the object and a test texture.

You can see in the screenshot here how it has been made, make sure you use one of the Transparent Materials, and ya, it’s double sided…

Best of luck…

EDIT: To UT Community, please scroll down a few posts to get a better version of this very simple object - we found out this one is not quite square…

265400--9547--$simplediscdoublesided_865.jpg

9

Hi Dingo,

Thats really really good. Very Much appreciated!

I’ve just come in from a curry and tried it and it looks great.
I gather I can create a texture sized 256 x 256 and apply it in the same fasion?

I have some of my images that will be used, so will try with them too.
Many Thanks.

All the Best,
Halo

10

what ever texture you apply can be any permitted size and will fit in the centre, you can offset in the material settings if you need to…

11

Thanks Dingo,

I just tried with my test image, and it looks great.

The only thing is I have applied a rotation script to it, but it doesnt rotate.
I dragged the DiscObject into the scene view and applied the texture, but no movement appears.

I have parented the DiscObject to a new Ga
meObject, should I just drag it into scene view or do I need to Parent it? Or make it a rigidbody?

You mentioned the offset setting, I gather this will enable an image to be moved left/right/up/down over the discobject to show a different part? For example if I placed an image onto the discobject and only wanted to show the bottom left corner, would that work through the offset setting?

Can the transparent shader option be used on Iphone? As I may be us
ing Iphone with this but would still like to keep the transparency.

Once again, thanks for the great help on this one.

12

I’ve just managed to get the disc to rotate, however it bobs up and down while rotating. Just wondering whether this is a problem with my object orientation not being perfectly correct?

13

If you are only rotating around one axis, as long as the model origin is central, it shouldn’t bob. Did you mention parenting the model to another GameObject, maybe the has caused it. Without seeing your rotation code and your editor setup it’s hard to tell.

Have you aligned your object in the parent ok? do you even need to join it to another object?

14

You are right, I dont need to parent it. I have unparented it, but still get some bobbing effects. I have the scale all at the same value, I probably need to make sure that it is exactly facing the camera.

Is there any simple way of aligning objects so that their rotation transform is correctly facing the camera?

I have been using the rotate option in Unity editor but cant seem to get it 100% correct.

15

you could make the object as a child of the camera, then it’s rotation and position will be relative to the camera, change the values as needed, then un-child it.

16

Hi RobbieDingo,

I’m getting on really well with the UV mapped disc. The only thing I cant figure out is that when rotating it, the disc appears to roll up and down slightly during a full rotation. I was hoping that maybe I just hadn’t aligned it properly but have attached it to the main camera as a child object and changed it’s position to equal the main camera, but it still bobs up and down a little while rotating.

Could it be because it is based on a cylinder? Or maybe my alignment is still wrong.

I have x,y and z all set to scale at 100.

Any suggestions?

17

I gather the DiscObject is a perfect Circle? Just a thought.

18

Hi, I suspect that the problem is that the circle (ie. the image on the texture) is not 100% in the centre of the object texture.

Make your own texture, an exact square (eg. 256 x 256 px) and make sure that the circle you draw on the texture is in the exact centre - then test that?

19

Hi,

I have a blank transparent background sized at 256x256 in photoshop, then pasted the circular picture into the centre of the transparent background, then saved and tried again.

I beleive that photoshop automatically centres it when you paste into a new window, and have tried counting the little squares on either side, which appear to be the same.

No joy unfortunately !

If you place the texture on the DiscObject it appears correct, but when rotating it will move up then down a little. Almost like a squashed circle would appear if roatating. I placed it just underneith a line drawn in the background, and when it rotates you can see it move up over the line then down then finish back in central position.

It’s a strange problem, any other thoughts?

P.S. just for reference, does the texture always have to be circular on a transparent background to work, or could I use a rectangular / square texture?

20

I have just found out that when copying using the eliptical tool it may create a non-perfect circle, so I Have to hold shift down while in Photoshop to create a Perfect Circle Copy of the image, just wondering whether there is a similar option in your modelling program? and whether the DiscObject was created Eliptical instead of a Perfect Circle?

Anychance you can double check, just in case?