ray-cast / ies

Convert the IES file into a IES texture for IES lightning

Hi there, I am a SDE.

🏢 Job：Graphics, engine, art.

🛠 Favorite languages：C++ and Hlsl.

💬 Good languages: C++、Hlsl、Glsl、Rust、TypeScript、nodejs、C#（Programming without any language limitations）

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🎨 Side projects：Technical artist、Graphics Engine

ies's Issues

IESLoadHelper的saveAs2D函数的data参数

请问IESLoadHelper的saveAs2D函数的data参数是干嘛的

Unable to properly sample IES light on the CPU

Hello,

I am trying to add IES lighting to my CPU renderer. To do so i used your IES parser.
Unfortunetly i am getting wrong results when i sample the lights(IESLoadHelper::interpolatePoint or IESLoadHelper::interpolateBilinear).

For example:
The ground truth: https://imgur.com/CrxT7bv
The result I get: https://imgur.com/pJ7VU5e

My renderer use a right handed Y up coordinate system:
https://i.stack.imgur.com/vg1P7.png

Here is my sampling code:

`

Math::Vec2 dirToSphericalUV(const Math::Vec3& dir)
{
	return Math::Vec2(
		0.5f + 0.5f * atan2(dir.x, dir.z) / 3.1415926f,
		1.f - acos(dir.y) / 3.1415926f);
}

struct SampleToLight
{
	Math::Vec3 L;
	float length;
	float intensityMultiplier = 1.0f;
};

SampleToLight IesLight::generateSampleToLight(const Math::Vec3& P) const
{
	const Math::Vec3 lightWsPosition = this->readPosition();

	SampleToLight sample;
	sample.L = lightWsPosition - P;
	sample.length = glm::length(sample.L);
	sample.L /= sample.length;

	//NOT WORKING
	const Math::Vec2 profileUV = dirToSphericalUV(-1.f * sample.L);
	const float profileCoordH = profileUV.x * (float)m_iesFileInfo->anglesNumH;
	const float profileCoordV = profileUV.y * (float)m_iesFileInfo->anglesNumV;
	sample.intensityMultiplier = m_iesLoadHelper.interpolateBilinear(*m_iesFileInfo, profileCoordH, profileCoordV);

	return sample;
}

`

Thanks in advance for helping.

能把IES文件的渲染效果转为PNG格式吗

能把IES文件的渲染效果转为PNG格式吗

IES Profiles with -1 luminance

A few ies profiles i have downloaded have the IES -1 for luminance value and so the loader was failing to load them in.

I have removed this check since total lumens is not used anywhere else and we have our own value for light intensity anyway not being fed by the lumen value of the ies profile.