{"id":6796,"date":"2021-10-31T16:57:00","date_gmt":"2021-10-31T16:57:00","guid":{"rendered":"https:\/\/renderguide.com\/?p=6796"},"modified":"2022-01-01T20:47:31","modified_gmt":"2022-01-01T20:47:31","slug":"blender-physics-simulation-tutorial","status":"publish","type":"post","link":"https:\/\/renderguide.com\/blender-physics-simulation-tutorial\/","title":{"rendered":"Blender Physics Simulation Tutorial [2024]"},"content":{"rendered":"\n

This Blender Physics Simulation Tutorial show how to do all kind of physic simulation with Blender. We will cover physic properties, rigid body, collisions etc.<\/p>\n\n\n\n

The main interface for handling Physics in Blender<\/a> would be the Physics Properties tab of the Properties Editor<\/strong>. There you can find all kinds of simulations that can be applied to the selected object.<\/p>\n\n\n\n

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Also, Physics can be applied as modifiers<\/strong> in the according tab. But there is little to no reason<\/strong> for doing this because all settings for these Physics would be in the Physics Properties tab only.<\/p>\n\n\n\n

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We saw that there are several different simulations<\/strong> that we can apply. So let\u2019s try them out one by one and learn how they work.<\/p>\n\n\n\n

Rigid Body Physics<\/h2>\n\n\n\n

I want to start this from the simpler simulations<\/strong>, that is why I have chosen a Rigid Body<\/strong> simulation. All it does is make it a physical object that will obey the laws of physics<\/strong>. So after applying it and playing animation, we can see that it simply falls.<\/p>\n\n\n\n

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For it not to fall infinitely into the abyss – we need to add another rigid body object<\/strong>, so they could interact. In the settings of this object, you should change its type from Active to Passive<\/strong>. <\/p>\n\n\n\n

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This means that the object will stay in place, instead of falling<\/strong>. So it is the type suitable for walls, floors, etc. It stops Cube from falling infinitely and instead, it lands <\/strong>on the Passive Rigid Body.<\/p>\n\n\n\n

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Using the Physics settings it is possible to change the mass<\/strong> of the object. Maybe make it heavier so it would push out lighter ones. Also, you can alternate the collision<\/strong> shape <\/strong>here and even how it will interact with the surface in a matter of friction and bouncing<\/strong>.<\/p>\n\n\n\n

Using Rigid Bodies and their settings, you can create mini-scenes like the one below.<\/p>\n\n\n\n

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Notice how the monkey pushes everything out<\/strong> of its way. This happens because the monkey object is the heaviest out of them all.<\/p>\n\n\n\n

Collision Physics<\/h2>\n\n\n\n

Next is Collision Physics<\/strong>. This one is very self-explanatory – it just makes selected objects collide with other objects<\/strong>. It is basically the same thing as a Passive Rigid body, the only difference is that a Passive Rigid Body interacts only with other Rigid Bodies<\/strong>, while Collision will work with all other simulations<\/strong> like Cloth, Fluid, etc. But would not work with the Rigid Body.<\/p>\n\n\n\n

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Rigid Bodies falling through Collision, while Cloth object stops<\/p>\n\n\n\n

Force Field Physics<\/h2>\n\n\n\n

Force Field<\/strong> creates a constant force around the selected object<\/strong>. By default, it is a pushing force<\/strong>. I have applied this simulation to the plane and increased the strength a lot, so it would affect my rigid bodies. <\/p>\n\n\n\n

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We can see how everything gets pushed outwards<\/strong> from the plane. Everything except the Suzanne object, because as I have already mentioned – it is very heavy. So the strength of the force field is not enough to push it.<\/p>\n\n\n\n

The main feature of Force Fields is that it has a lot of different types<\/strong> that you can use. Each type is unique and has different effects on the scene.<\/p>\n\n\n\n

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There are 13 types<\/strong> available at the moment. I won\u2019t go over all of them. Besides, not all of them are equally useful and interesting. I would recommend you test out these types<\/strong> yourself if you are interested in using Force Fields. <\/p>\n\n\n\n

Some illustrative examples: Wind Force Field<\/strong> is very similar to the default Force one. The main difference is that Force pushes into all directions from the object. While Wind pushes only one way<\/strong> – where the object is directed to. Lower you can see how all objects are pushed upwards, instead of all directions.<\/p>\n\n\n\n

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Another cool example is the Vortex type<\/strong>. It looks totally different from the previous two. It does not push objects upwards at all, instead, it pushes everything away from the object in a vortex motion<\/strong>.<\/p>\n\n\n\n

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Blender Cloth Physics<\/h2>\n\n\n\n

Cloth physics makes objects behave like they are made of cloth<\/strong>. So it would be soft and fold<\/strong> under the push of gravity, itself, or other objects. It is a very important and huge part of using physics<\/strong> in Blender, so we dedicated not one, but two articles to this theme. Blender Cloth Simulation Tutorial<\/a> to learn about regular Cloth Physics. And Blender Cloth Brushes Tutorial<\/a> to learn about brushes that are available in the Sculpting menu.<\/p>\n\n\n\n

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From Blender Cloth Simulation Tutorial<\/a><\/p>\n\n\n\n

Blender Dynamic Paint Physics<\/h2>\n\n\n\n

This one is very weird<\/strong>. Dynamic Paint allows you to turn objects into canvases and brushes<\/strong>. Then these brushes can influence canvases<\/strong> in some manner. For example, you can create prints of the brush on the canvas. Or you can create waves made by brush <\/strong>as if the canvas is made of liquid.<\/p>\n\n\n\n

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Brush sphere creating waves on a canvas<\/p>\n\n\n\n

Also, you can straight up paint <\/strong>with the brush or even displace<\/strong> geometry<\/strong>. The big problem is that using this simulation can be difficult and convoluted<\/strong>. But if you manage to make it work – it can be very useful.<\/p>\n\n\n\n

Blender Soft Body Physics Physics<\/h2>\n\n\n\n

Soft Body<\/strong> is a weird one. When you add it to an object, you expect that it would be the same as a Rigid Body, but soft. But when you try it out – it is not like that at all. Instead, the object does not even fall<\/strong> under gravity and stays where it is. At the same time, it starts going up and down without much going on.<\/p>\n\n\n\n

This is because just in itself, Soft Body simulation is not interesting. But when you have something that it can interact with<\/strong> – it becomes much more interesting. Even if it is something as simple as adding an object for it to collide with.<\/p>\n\n\n\n

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It can be very similar to the Cloth simulation<\/strong> at times and it even can be replaced with it. But this simulation is important because there are a lot of soft things that are not made of Cloth<\/strong>. For example – our bodies, which are not static and instead jiggle <\/strong>with each movement. So it can be very useful for simulating human bodies jiggling.<\/p>\n\n\n\n

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Fluid Physics<\/h2>\n\n\n\n

Simulating fluids is fun<\/strong>! And also it is not that hard if you know what you are doing. Blender offers you to simulate not only liquids but even smoke<\/strong>. We have an in-depth Blender Fluid Simulation Tutorial<\/a> that explains everything you need to know to create fluid simulations yourself.<\/p>\n\n\n\n

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From Blender Fluid Simulation Tutorial<\/a><\/p>\n\n\n\n

Rigid Body Constraints <\/h2>\n\n\n\n

This one can only be applied to an object that is already a rigid body<\/strong>. What it does is connect two rigid bodies<\/strong>, so one would influence another. For example, the cube and the sphere are connected. So even though the cube falls on the plane, it then gets dragged<\/strong> down by the falling sphere.<\/p>\n\n\n\n

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But if I make the Cube weigh a lot more than the sphere – the sphere would not have enough force<\/strong> to move the Cube. Instead, the sphere would be locked in place as soon as the cube hits the ground and stops.<\/p>\n\n\n\n

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Additionally, there are several types of constraints here<\/strong>. For example, instead of the default one, you can make it so it will be connected to a point. This means that the sphere would not fall, nor stop. Instead, it would rotate around the stopped Cube like a pendulum<\/strong>.<\/p>\n\n\n\n

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Blender Gravity<\/h2>\n\n\n\n

A lot of physics we showed are dependent on gravity<\/strong>. By default, Blender has an Earth gravity<\/strong>. But what if you want to change that? It is fairly easy. All you need to do is go to the Scene Properties and find the Gravity section.<\/p>\n\n\n\n

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Here you control whether there would be any gravity, in which direction it would pool, and with how much force. So you can apply, for example, moon gravity<\/strong> to the scene and see how it changes everything:<\/p>\n\n\n\n

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Moon Gravity scene<\/p>\n\n\n\n

Baking Blender Physics Simulation<\/h2>\n\n\n\n

Some simulations can be baked into keyframes<\/strong>. This means that simulation would be saved as animation and would not be calculated each time<\/strong> you change anything anymore. This option is usually found in the Cache section<\/strong> of the Physics Simulation you are working with.<\/p>\n\n\n\n

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Not all simulations have this section<\/strong>, though. Only the more difficult ones to calculate, such as Fluid and Soft Body. Here you select the start and end frame<\/strong> that you want to save and press Bake.<\/p>\n\n\n\n

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After this, simulation is baked into keyframes and it will be left as is<\/strong> until you delete the cache. I would recommend you to always bake your final simulations<\/strong>, as it can be better for rendering and minimizes glitches <\/strong>and other problems.<\/p>\n\n\n\n

Conclusion – Blender Physics Simulation Tutorial<\/h2>\n\n\n\n

Blender Physics Simulation is very powerful and can be huge timesavers<\/strong>. This is the thing that I would recommend anyone to look into<\/strong> and research for themselves, as you may never know which part of the work can be calculated automatically for you.<\/p>\n