Chapter 11 - Tessellation by distance - empty render

Hi, did anyone have an issue in Chapter 11 when calculating the tessellation by camera distance, where after completing the code in the chapter it renders only a white screen?

I redid the chapter twice to make sure I didn’t make a mistake, but still the screen is white.
The previous steps for rendering the tessellation ( including the red bottom-left patch ) do render correctly. Only after rendering the tessellation by camera distance does nothing appear on the screen.

What could the issue be?

Edit: The consequent steps of using a height map also result in a white screen.

Hi @icipiracy

Does the supplied final project work for you?

If you’re using a MacBook Pro without a discrete GPU card, that might be the problem. Integrated Intel GPUs may not work well with tessellation (although I would have to look into that further to be more definite about it).

Hi @caroline

Yes the final project does work. Tried comparing the code between my own and the final but it’s hard to run down everything.

Now that I think of it, I think using the frame capture in XCode could be a good way to debug this?

Thank you for answering here Caroline! I’m really enjoying the book so far.

I don’t know that the frame capture will help here, depending on what the error is of course. You could try it and see. PM sent.

And I’m glad you’re enjoying the book :smiley:

I’m also having this problem. Same section, empty render, combed over the code twice and can’t see any discrepancies. (I’m comparing to the code in the Final project and the only differences I see are those that I assume come further in the chapter…)

If you can zip it up and upload it, then I’ll take a look at it. What are your hardware / software specs?

Thanks Caroline. I’ve advanced it to the end-of-chapter state now, but it’s still not rendering anything, while the included final chapter project does. I’m looking over them trying to locate the difference.

I’m using Xcode Version 12.0 beta 2 (12A6163b) on a 2018 13" Macbook Pro, OS 10.15.5. Let me know if you want more details.

Hmm, it appears I’m still a “new user” and can’t upload things yet…

I’ll keep looking if you don’t have time, it’s got to be in front of me somewhere…

@barnetta Do you still have issues with this?