Effective bloom in OpenGL for Sol Trader
TL;DR
Skip to the pictures.
I’ve been working on and off on Sol Trader (C++ version) for about a month now. At the beginning of this week, I’ve been coded up an effective type formatting system using freetype2 natively with OpenGL, which is now in and showing even rather esoteric fonts nicely.
The second half of this week was spent adding on a bloom filter to the graphics engine.
Bloom filtering: making your world stand out
A bloom filter causes bright areas of the image to ‘take over’ their surrounding area, simulating the high dynamic range of real light. It stops your game world from looking dull and flat and really makes it stand out. See this article for some nice screenshots from Tron 2.0 - it can also be used for all sorts of glow and blur effects.
So how’s it done? The trick is to render your scene to a texture, rather than to the screen. Once you’ve done that, you blur and downsample that texture a few times, and then display the results combined with the original texture.
Specifically, this is the process my bloom filter follows:
- Render to a texture
- Copy that texture to two more textures, one a quarter of the screen size, and one an eighth of the screen size.
- Blur the two smaller textures using gaussian blur. There are clever techniques which mean you only need six texture lookups to perform a 5x5 gaussian blur. Texture lookups are expensive, so it’s worth doing as few as possible.
- Add all these textures together and add an exposure function to cause the white to saturate for strong color values.
Writing the initial bloom filter was fairly easy. Making it fast was hard: you have to work at combining the different aspects of the effect to get what you want, with the absolute minimum of effort for your graphics card. My first attempt ran at a paltry 27 frames a seconds, although it looked very nice: I eventually managed to get it to the point where it runs in roughly 150 frames per second and still looks 80% as good.
What's the result?
A picture is worth a thousand words, so here are three:
I’ve deliberately upped the bloom exposure to show off the effect: it is much more obvious when it’s moving. Hopefully you can see the volcanic eruptions on Venus are making the outline of the players’ ship that much more hazy. The label of the planet also currently has the bloom effect applied: I’ll be able to turn that off when I have a more functional GUI in place.
I plan to use this effect for all sorts of things: laser fire, explosions, you name it.
Next…
I’m going to tackle the gui. I now have AI characters with names trading on Earth’s main commodity market: it’s time the player joins them in making trades.
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Ealdorlight: A Kickstarter retrospective
It’s now been over three months since the end of the Ealdorlight Kickstarter campaign. I’ve deliberately been taking some time to think and learn from the fact that it didn’t reach the target, and to work out what to do next. Frankly, I was pretty upset that the campaign didn’t make it, and it’s taken a while to get over it.
It’s also taken a while to think through the campaign properly. Some things are obvious in hindsight, and others less so. A lot of post-Kickstarter analysis feels like a stab in the dark. Nevertheless I’ve given it a lot of thought, and these are my best guesses for why I think Ealdorlight’s Kickstarter failed:
Read moreEaldorlight's Kickstarter is live at 4pm today
The sixth of June is a significant day for me personally. In 2004, I spent the entire of the day in hospital. I remember the 60th anniversary commemorations of D-day on the TV in the background, as I sat beside my wife, in labour with our first child. I became a father an hour after midnight on the 7th June; my son becomes a teenager tomorrow.
Twelve years later, in 2016, I spent the entire of 6th June glued to Steam watching and waiting whilst my first game Sol Trader was released to the world. This was a career dream come true: since I started programming at six years old I’d always wanted to create and ship my own games. Sol Trader’s release was ultimately a painfully formative experience for me, which I wrote about at the time and was interviewed about recently in GamesIndustry.biz.
Over the last year, I’ve been keeping busy doing two things. One is to support Sol Trader as much as I can with countless updates and patches. I’ve also been very busy working on a new game, Ealdorlight, a medieval RPG-style take on Sol Trader’s mechanics, with turn-based combat, realistic damage and great graphics. I announced Ealdorlight in March and demonstrated it at Rezzed, strengthening my hope that the idea was a good one.
I decided fairly early on that I wanted to take Ealdorlight to Kickstarter. Sol Trader’s successful Kickstarter was a brilliant experience. The Kickstarter community is one of the kindest, most positive on the Internet. I also needed funding for this game: Sol Trader was self-funded through many long evenings and contracting work, and for Ealdorlight I need a bigger team to realise the vision. It’s built in Unreal Engine 4, which simultaneously saves me loads of development time and means I need a bigger team to pull off the realistic art style I’ve gone for.
As time came near to launch, the first anniversary of Sol Trader’s released seemed an appropriate day to launch the campaign. So today, 6th June 2017, I will spend the entire day glued to Kickstarter as my campaign goes live at 4pm today.
Visit Ealdorlight’s Kickstarter Campaign
There’s plenty more about Ealdorlight on the campaign - head over there and read all about it! A huge amount of work has gone into it, and I’m very grateful for all the support and help I’ve received from the team I’ve put together, and for friends and family who have given me endless encouragements and feedback.
This post is a little earlier than 4pm so that you can watch it go live if you want. Earlier backers get lower edition numberings on some of the rewards, so you might want to be there from the start!
Read moreHow Ealdorlight's story stands out
As we head towards the Kickstarter campaign launch on June 6th, I want to talk a little about the story behind Ealdorlight works.
The basic story stays the same for each game: you are discovered wandering through a remote village at a young age, and realise your destiny is to overthrow the King. However, like in Sol Trader, every person you meet is randomly generated. This means that your real identity will be different every time, and you’ll have to discover it all over again every time you generate a new game.
Handcrafted story in a random world
The trick is layering a great story on top of a generated world with random characters. Building empathy with the main character and his family when all characters are generated is hard, and hinges around being able to hook the story in at the right moments.
My plan is to write plenty of tightly connected story arcs that are triggered on events that happen during history generation. These will in turn trigger future quests the player can undertake. Not all story-arcs will appear in every game: it will depend on how the history generation goes. I will constrain things such that there is always a route through the game, and that players always have a way to overthrow the King, even if that might be easier or harder depending on the starting setup. These story-arcs then should interact with each other, hopefully producing a unique path through the game.
Identity
Ealdorlight is set within a low fantasy world, and there’s no traditional magic. The player gets more powerful through discovering key pieces of knowledge about their past. These insights into of your real past feed directly into your character’s stats, skills and abilities.
I’ve long been fascinated with identity: knowledge of who we truly are affects many areas of our lives for the better. In Ealdorlight I wanted to tell a story which takes this to an almost supernatural level. By removing the player from their birth family, they start as an entirely normal person within the world. It’s only after their early game encounter with the Ealdorlight and the discovery of their past that things begin to change.
Much more on this to come, but in the meantime, here’s a glimpse of our story’s beginning.
Ealdorlight: backstory teaser (updated)
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Ealdorlight Kickstarter on 6th June, Sol Trader 1.3 released
I am now back from some extended time away after Rezzed, both on holiday with the family and training some clients away from home. I’ve released Sol Trader 1.3 today, and set the Kickstarter for Ealdorlight to 6th June.
Rezzed was fantastic: it was great to see lots and lots of people wearing our Ealdorlight crowns. We ran out of crowns on both days, with some creative head displays on offer:
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Ealdorlight Kickstarter launch date: 6th June
Yes, I know I said May :) I’ve decided to go for a 31-day campaign, starting on the 6th June, for a few reasons:
- It doesn’t clash with any major US holidays, like Memorial Day. The 48-hour reminder email should go out on the day after 4th July.
- I want to give myself the best chance of success by polishing the combat demo hard. It was great to get such good feedback at Rezzed and I think it’ll be a great hook. I need more time to do that well.
- 6th June is the first anniversary of Sol Trader’s launch, so it ties in nicely with the ongoing Revelation Games story.
I’m excited and nervous about this Kickstarter campaign: my third one to date. After succeeding last time I’m really trying to take my time and get it right.
Sol Trader 1.3 released!
Now that I’m back, I’m able to support a new release of Sol Trader: 1.3 is now finally released after a length beta period.
Here are the highlights:
- You can now chat to characters directly on the right if they’re in the same location as you
- Pirate Chief and criminals are now more likely to try to destroy you
- Fix a bug where you’re not paid enough for a mission
- Dignitaries now fly around a little less than before to make it easier to pin them down
- Inter-faction missions now pay slightly less
- Business trips now pay slightly less
- Taxi missions now pay slightly more
- Talking to your criminal parents will no longer cause them to forget who you are
- Fix crash where a character develops an opinion of the player mid-conversation
- Fix crash when showing GUI for a ship the AI is driving
- Fix crash where a character would attempt to sell a good on a ship they’ve lent to the player
- Can now initiate conversations when paused - will restart the game but at realtime speed
- Fixed the Tiger II achievement
Your steam copy should automatically update. I’ll be releasing an updated downloadable version to SendOwl in the next few days.
Read moreIntroducing: Ealdorlight
I’m very excited to be able to announce my new game…
Ealdorlight is a single player RPG set in a low fantasy kingdom where you must influence, cajole and fight your way to the throne.
Players travel the land, meet characters, perform quests and attempt to discover their true identity, different every game. Learning about the pasts of other characters gives the player influence over them, and learning who they truly are allows a player’s character to become more and more powerful. Along the way they will discover ancient weapons with hidden pasts, recruit allies, fight those who get in their way, and finally build a strategy to overthrow the King.
Ealdorlight generates centuries of history and society each game, giving players a whole kingdom of characters and relationships to explore and exploit, with turn based story-focused combat and an open quest structure.
Find out more info on the website!
Development plan
The plan is to put the game back on Kickstarter in May. Kickstarter was awesome last time for Sol Trader’s campaign - I think that the Kickstarter community is one of the best on the Internet for encouragement and positivity. I also want to check in with gamers to make sure the game I’m planning is the one people want me to make.
I’m building this game in Unreal, although parts of Sol Trader’s engine will make it into the game. Using Unreal has been a great experience so far. I’ll post tips and other learnings here as I go, as well as some thoughts on why I chose it.
I’ve already had some very helpful feedback on the idea and am looking for more - what thing about Ealdorlight most draws your attention?
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