Adding material

Graphics Shaders & Materials
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1

I can add an image to an object using this:
var img = Resources.Load(“Images/”+“test image”);
testobject.GetComponent().sprite = img;

Which works, but when I try adding material, although it doesn’t throw up any errors it doesn’t do anything, the material slot is still empty on runtime.
I’m adding material like this:
testobject.AddComponent();
var mymat = Resources.Load(“Images/”+“spritediffuse”);
testobject.GetComponent().material = mymat;

What am I doing wrong?

2

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Honestly, just sounds like you have a bug. Start here:

Time to start debugging! Here is how you can begin your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

- the code you think is executing is not actually executing at all <— my first guess

  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is
  • you’re getting an error or warning and you haven’t noticed it in the console window
    - something is null, such as that material you’re trying to load. <— my second guess

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the names of the GameObjects or Components involved?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer for iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

If your problem is with OnCollision-type functions, print the name of what is passed in!

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

“When in doubt, print it out!™” - Kurt Dekker (and many others)

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.

3

Turns out it wasn’t a bug. I should have been changing the Image material instead. Overlooked. What I’m trying to do is get at the properties of the 2d sprites default material so I can brighten individually, since as it stands, if I use this with most of my images, they are all globally affected by light2d and I want to control the brightness on the images individually. I can do this with another URP but I have do make a material for each image and attach it as basemap. I want to use the same default for all of them and be able to change via script and also then they can be affected globally as well.

The only material I know affected globally by Light2d is urp 2d sprite lit default

4 
GetComponent<Renderer>().material.color*=1.2f; // brighten "individual" material's color

GetComponent<Renderer>().sharedMaterial.color*=1.2f; // brighten "global" material's color
5

Thank for this. I’m not sure I explained properly in my previous post. Problem I have is that I wanted to change the brightness to an intensity higher than is available in the default materials. So I used a urp material I made for all of my images, attaching the images in basemap, so I have a material for each essentially that I can brighten. But these are not affected by Light2d globally. As I said in my previous post, the only material I know is affected is sprite lit default. I tried changing the intensity via script on sprite lit default but so far couldn’t get it to work. Can change the colour but not the intensity.

Maybe I’m doing something wrong but GetComponent().material.color*=1.2f doesn’t seem to work on sprite lit default.

6

It’s possible that URP does things differently but in Built-In I can increase the color of materials past 1.0. But I have noticed that the color is clamped at 1.0.

            GetComponent<SpriteRenderer>().color*=1.5f; // won't go higher than 1.0
          
            GetComponent<Renderer>().material.color*=1.5f; // brightness increases beyond 1.0
7

Thanks again. By tinkering with things finally got it to change the image intensity but now this has caused another issue (as always with unity, I’m beginning to discover) in that the image now flickers badly. :eyes:

8

It seems the issue you’re having is that you want both a global sprite brightness and a individual sprite brightness active at the same time. Perhaps there’s a workaround?. For example, if you want a global brightness setting simply because you want to fade all your sprites to black at the end of the game then there’s other ways to do that…

9

Been struggling with this for a couple of days so thanks for all your help. Appreciate it. I got the flickering to stop by deselecting HDR in my render pipelines quality tab. Don’t know why this would stop the flickering, perhaps to do with my rubbish graphics card which is an antique. I plan to take my graphics card on Antiques Roadshow soon :slight_smile: