- 180
- GTP_DarthDrift
Hey guys. I love GT5P but I had gotten bored with it a few months back for all the reasons that are well documented in the forum. I decided to try iRacing đź‘Ť. Because of the quality of the iRacing physics, graphics, great online racing, much less punting (hits your safety rating), damage, replays, qualifying, tire wear, fuel usage, pit stops, track modeling, comprehensive statistics, variety and coordination of events and enthusiastic community, I have rarely even thought of GT5P since. The purpose of this thread is not to rave about iRacing or knock GT5P (I love them both), but rather to share an iRacing forum thread from the designer of iRacing. The topics are upcoming updates and damage. I'm sharing this for two reasons:
1) iRacing gets updates just like GT5P and it's interesting how much more info gets shared with users. Perhaps PD will consider sharing more to keep interest up...speculation gets tiring after a while.
2) The damage modeling technical concept from iRacing is explained here. Their modeling is excellent, although perhaps too sensitive to low speed contact. It definitely promotes clean driving as even a light punt or contact with a wall will damage your car
and likely eliminate your chance for a Top 5. It's probably too late for PD to incorporate any of this, but who knows, maybe PD will do it better...
Anyway, just thought I would share this because it sums up why I've stopped playing GT5P. I'll keep checking the forums because I really do like GT5P and the community here, and I'm looking forward to the full version of GT5! Happy Racing!!!!
From Dave Kaemmer - 11 Sept 2008
1) iRacing gets updates just like GT5P and it's interesting how much more info gets shared with users. Perhaps PD will consider sharing more to keep interest up...speculation gets tiring after a while.
2) The damage modeling technical concept from iRacing is explained here. Their modeling is excellent, although perhaps too sensitive to low speed contact. It definitely promotes clean driving as even a light punt or contact with a wall will damage your car
and likely eliminate your chance for a Top 5. It's probably too late for PD to incorporate any of this, but who knows, maybe PD will do it better...Anyway, just thought I would share this because it sums up why I've stopped playing GT5P. I'll keep checking the forums because I really do like GT5P and the community here, and I'm looking forward to the full version of GT5! Happy Racing!!!!
From Dave Kaemmer - 11 Sept 2008
Hello fellow iRacing Members:
As much as I enjoy working on the iRacing code, physics, tire modeling, the competition structure and new models and features, I also enjoy reading the forum posts as often as I get a chance. I often read the posts debating what should be next or to be blunt what is going on inside the walls of iRacing. After all these years, I guess I should not be surprised that my passion for sim racing is shared by so many people. That is a good thing! It certainly gives me the chance to do what I love.
I really do appreciate the passion for what is coming next at iRacing. We really donÂ’t have any big secrets (although we are working on some pretty cool surprises for next year). We are simply hard at work on the things that both you and we want for the service. Some of the bigger feature-related items that we are currently working on were included in one of the questions in our recent survey. Those items include pitting, flags, race control, replays and open practice. Some of these items should be out soon. I hope they ALL will be out soon, but in this business things never go as planned. It is a very complicated and technically challenging endeavor. I have learned not to make promises if IÂ’m not 100% certain weÂ’ll be able to deliver.
Anyway, we will post the results of that survey once we wrap it up – in case you’re curious. Thanks for taking the time to do it; the results are very helpful to us. We also have some very exciting new cars and tracks that we will be announcing shortly and bringing into the sim. I hope you saw the Lotus 79 announcement this week.
I was going to wait until we added blogging and social-network functionality to iRacing and then start a weekly developerÂ’s blog and let the technical, production and design teams here rotate and tell you the nitty gritty as to what they are working on and discuss some of the more technical aspects of iRacing, since there seems to be a portion of the membership interested in that detail. We should have the blogging capability done and up live on the site in a few weeks or so, but in the meantime, I figured I would send out at least a few quick development thoughts each week. Again, some people do seem interested in the details, so I asked Kevin Combs our 3D Art Manager and a terrific technical artist to talk about our collision system (below), one of the many models within iRacing. Hope you enjoy. Talk to you next week and good racing!
Dave
Our collision system is unique compared to systems used in the past. Rather than using a static collision volume to represent the driverÂ’s car, each car has a collection of spheres created by the artists, which represent the carÂ’s solid surface. Each sphere is animated to match the deformation of the visual model, so if you crunch the nose of your race car out of its normal position, the collision will be moved back to match its new position the next time you hit something. The graphical animation of the sphere also controls the damage assigned to the visual model, which in turn controls the damage texture drawn on the model.
Each sphere is imported from the graphical model into the physics definition for each car where physical characteristics such as the material type (plastic, steel, aluminum, carbon fiber, fiberglass, rubber, etc.), material strength, and its breaking point are defined. When a sphere exceeds its breaking point it is removed from the collision detection and any visual model associated with the sphere is detached from the car. In the future, visual models that are detached will remain in the world with their own collision spheres and mass; creating debris that is hittable and can cause damage to other cars.
Although the spheres themselves determine collisions between the driver and the world, as well as the driverÂ’s collisions with other drivers, the remote cars use a convex hull defined by the spheres for performance reasons; in a full field of cars, if all cars used the collision spheres, there would be thousands of sphere collision calculations. Spheres that surround your wheels and tires are treated specially, since the tire forces use a much more sophisticated force model.
As much as I enjoy working on the iRacing code, physics, tire modeling, the competition structure and new models and features, I also enjoy reading the forum posts as often as I get a chance. I often read the posts debating what should be next or to be blunt what is going on inside the walls of iRacing. After all these years, I guess I should not be surprised that my passion for sim racing is shared by so many people. That is a good thing! It certainly gives me the chance to do what I love.
I really do appreciate the passion for what is coming next at iRacing. We really donÂ’t have any big secrets (although we are working on some pretty cool surprises for next year). We are simply hard at work on the things that both you and we want for the service. Some of the bigger feature-related items that we are currently working on were included in one of the questions in our recent survey. Those items include pitting, flags, race control, replays and open practice. Some of these items should be out soon. I hope they ALL will be out soon, but in this business things never go as planned. It is a very complicated and technically challenging endeavor. I have learned not to make promises if IÂ’m not 100% certain weÂ’ll be able to deliver.
Anyway, we will post the results of that survey once we wrap it up – in case you’re curious. Thanks for taking the time to do it; the results are very helpful to us. We also have some very exciting new cars and tracks that we will be announcing shortly and bringing into the sim. I hope you saw the Lotus 79 announcement this week.
I was going to wait until we added blogging and social-network functionality to iRacing and then start a weekly developerÂ’s blog and let the technical, production and design teams here rotate and tell you the nitty gritty as to what they are working on and discuss some of the more technical aspects of iRacing, since there seems to be a portion of the membership interested in that detail. We should have the blogging capability done and up live on the site in a few weeks or so, but in the meantime, I figured I would send out at least a few quick development thoughts each week. Again, some people do seem interested in the details, so I asked Kevin Combs our 3D Art Manager and a terrific technical artist to talk about our collision system (below), one of the many models within iRacing. Hope you enjoy. Talk to you next week and good racing!
Dave
Our collision system is unique compared to systems used in the past. Rather than using a static collision volume to represent the driverÂ’s car, each car has a collection of spheres created by the artists, which represent the carÂ’s solid surface. Each sphere is animated to match the deformation of the visual model, so if you crunch the nose of your race car out of its normal position, the collision will be moved back to match its new position the next time you hit something. The graphical animation of the sphere also controls the damage assigned to the visual model, which in turn controls the damage texture drawn on the model.
Each sphere is imported from the graphical model into the physics definition for each car where physical characteristics such as the material type (plastic, steel, aluminum, carbon fiber, fiberglass, rubber, etc.), material strength, and its breaking point are defined. When a sphere exceeds its breaking point it is removed from the collision detection and any visual model associated with the sphere is detached from the car. In the future, visual models that are detached will remain in the world with their own collision spheres and mass; creating debris that is hittable and can cause damage to other cars.
Although the spheres themselves determine collisions between the driver and the world, as well as the driverÂ’s collisions with other drivers, the remote cars use a convex hull defined by the spheres for performance reasons; in a full field of cars, if all cars used the collision spheres, there would be thousands of sphere collision calculations. Spheres that surround your wheels and tires are treated specially, since the tire forces use a much more sophisticated force model.
. Similar to the post above on damage modeling, I quote Steve Myers, the Executive Director of iRacing below on the process for introducing new content in the sim. He goes into some detail on licensing, scanning cars and tracks and physics. 
