• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
gboxentertainment

Screen-space reflections camera angle issues

3 posts in this topic

I've tried to implement screen-space reflections and it seems to work but only at a very tight reflection angle:

 

[attachment=17858:giboxssr0.jpg]

 

Here's what happens when I inrease the camera angle to the surface:

 

[attachment=17857:giboxssr1.jpg]

 

And if you look at the image below, when I am facing the surface, it just renders the entire scene from the camera's point of view, instead of a reflection:

 

[attachment=17856:giboxssr2.jpg]

 

I understand that SSRs only render what the camera can see, so at larger angles from each surface, the reflection will disappear; however, in my case it seems to only work for very tight angles - I've seem implementations that still show a correct reflection at larger angles.

 

Here's my code:

	vec4 bColor = vec4(0.0);
	float reflDist = 0.0;
	vec3 screenSpacePos;	
	E = normalize(camPos - gsout.worldPos.xyz);
	reflDir = normalize(reflect(-E, bumpN));
	float currDepth = 0.1;

	for(int i = 0; i<20; i++)
	{
		vec4 clipSpace = proj*view*vec4(gsout.worldPos.xyz+reflDir*reflDist,1.0);
		vec3 NDCSpace = clipSpace.xyz/clipSpace.w;
		screenSpacePos = 0.5*NDCSpace + 0.5;

		float sampleDepth = texture(reflTex, screenSpacePos.xy).w;
		currDepth = (proj*view*vec4(gsout.worldPos.xyz+reflDir*reflDist,1.0)).z;
		float diff = currDepth - sampleDepth;
		if(diff < 0)
			bColor.xyz = texture(reflTex, screenSpacePos.xy).xyz;
		reflDist += 0.1;
	}

The reflTex stores the screen space rendering of the scene in the xyz components and length(camPos.xyz - worldPos.xyz) in the w component in a 32-bit floating point texture.

 

Would anyone be able to give me some tips on what I may be doing wrong?

0

Share this post


Link to post
Share on other sites

reflDist += 0.1;

that seems to be quite random, isn't it? depending on the scene's scale and distance etc. you could pretty much just sample the same pixel all the time. the distance you add should be about the size of a pixel.

or the other way around, for optimal results: project the start and end of the reflection ray to the screen, then step by pixel distance and calculate for every pixel the depth of the ray.

 

(ok ok, to be really optimal, you'd need to make the reflection ray "infinity", clip it by the near or far plane, depending on orientation, project it, clip it by the screen rect, and then step pixel by pixel with some line algorithm e.g. bresenham. But the above should already give you more correct results ;) )

0

Share this post


Link to post
Share on other sites

reflDist += 0.1;

that seems to be quite random, isn't it? depending on the scene's scale and distance etc. you could pretty much just sample the same pixel all the time. the distance you add should be about the size of a pixel.

 

I'm not quite sure what you are saying, because reflDist += 0.1 means that I am adding 0.1 distance of world space units to the ray direction. I add this to the starting position of the reflection ray - i.e. the world position of the pixel I am looking at. To give you a scale of things, my entire scene is about 2.0x2.0x2.0 world space units.

0

Share this post


Link to post
Share on other sites

I'm saying

1. 0.1 might progress you exactly 0 pixel in worst case, 1.0 in world space on a flat angle to the surface might not move far in screenspace if you go far away.

2. 0.1 might progress you 10pixel at a time, making you skip the object you actually want to reflect

 

beside that, your code looks algorithmically correct (ignoring optimization opportunities :) )

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0