# Ray March node
A simple ray marcher for primitive shapes.
**Controls**
|Name|Options|Description|
|---|---|---|
|SDF (Signed Distance Function)|SDBox, SDSphere, SDCapsule, SDCylinder, SDTorus|Signed Distance Functions for the space to draw.|
**Inputs**
|Name|Type|Binding|Description|
|---|---|---|---|
|signed distance|float|none|Signed distance calculated from Signed Distance Functions (SDFs)|
|ray origin|vec3|none|Ray origin|
|ray direction|vec3|none|Normalized ray direction|
|max steps|int|none|Maximum number of steps for ray marching|
|max distance|float|none|Maximum distance to march along the ray direction|
|distance threshold|float|none|Threshold to check against signed distance to determine the ray intersection point.|
**SDFs Inputs**
|Name|Type|Availability|Description|
|---|---|---|---|
|cube pos|vec3|SDBox|Position offset of the box shape|
|cube eulers|vec3|SDBox|Rotation of the box shape in Degrees|
|cube scale|vec3|SDBox|Scale of the box shape|
|sphere pos|vec3|SDSphere|Position offset of the sphere shape|
|sphere eulers|vec3|SDSphere|Rotation of the box sphere in Degrees|
|sphere scale|vec3|SDSphere|Scale of the sphere shape|
|capsule pos|vec3|SDCapsule|Position offset of the capsule shape|
|capsule eulers|vec3|SDCapsule|Rotation of the capsule shape in Degrees|
|capsule height|float|SDCapsule|Height of the capsule shape|
|capsule radius|float|SDCapsule|Radius of the capsule shape|
|cylinder pos|vec3|SDCylinder|Position offset of the cylinder shape|
|cylinder eulers|vec3|SDCylinder|Rotation of the cylinder shape in Degrees|
|cylinder height|float|SDCylinder|Height of the cylinder shape|
|cylinder radius|float|SDCylinder|Radius of the cylinder shape|
|torus pos|vec3|SDTorus|Position offset of the torus shape|
|torus eulers|vec3|SDTorus|Rotation of the torus shape in Degrees|
|torus small radius|float|SDTorus|Small radius of the torus shape|
|torus big radius|float|SDTorus|Big radius of the torus shape|
**Outputs**
|Name|Type|Binding|Description|
|---|---|---|---|
|distance|float|None|Ray intersection distance|
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**Extras**
This node is only simple ray marching example, the true power of raymarching can only be achieved by custom SDFs. At the moment I am unable to inject the custom code via visual shaders, so I have provided the custom template at the following location.
The default location can be found at
`res://addons/ShaderLib/RayMarching/RayMarchCustom.gdshaderinc`
You can copy the code from `RayMarchCustom.gdshaderinc` and then create a Global Expression node and paste it in your visual shader.
Lastly you also need to create an Expression node, define required input and output parameters and call the custom ray marching function as below.
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